diff --git a/Security/Member.php b/Security/Member.php
index 85534a58f..f838bf49c 100644
--- a/Security/Member.php
+++ b/Security/Member.php
@@ -1509,7 +1509,7 @@ class Member extends DataObject implements TemplateGlobalProvider {
 				)
 			);
 			$dateFormatField->setValue($self->DateFormat);
-			$dateFormatField->setDescriptionTemplate('MemberDatetimeOptionsetField_description_date');
+			$dateFormatField->setDescriptionTemplate('forms/MemberDatetimeOptionsetField_description_date');
 
 			$defaultTimeFormat = Zend_Locale_Format::getTimeFormat(new Zend_Locale($self->Locale));
 			$timeFormatMap = array(
@@ -1526,7 +1526,7 @@ class Member extends DataObject implements TemplateGlobalProvider {
 				)
 			);
 			$timeFormatField->setValue($self->TimeFormat);
-			$timeFormatField->setDescriptionTemplate('MemberDatetimeOptionsetField_description_time');
+			$timeFormatField->setDescriptionTemplate('forms/MemberDatetimeOptionsetField_description_time');
 		});
 
 		return parent::getCMSFields();
diff --git a/admin/code/LeftAndMain.php b/admin/code/LeftAndMain.php
index 4114b2003..e25baccf0 100644
--- a/admin/code/LeftAndMain.php
+++ b/admin/code/LeftAndMain.php
@@ -783,7 +783,7 @@ class LeftAndMain extends Controller implements PermissionProvider {
 						return $controller->renderWith($controller->getTemplatesWithSuffix('_Content'));
 					},
 					'Breadcrumbs' => function() use (&$controller) {
-						return $controller->renderWith('CMSBreadcrumbs');
+						return $controller->renderWith('Includes/CMSBreadcrumbs');
 					},
 					'default' => function() use(&$controller) {
 						return $controller->renderWith($controller->getViewer('show'));
diff --git a/admin/code/ModelAdmin.php b/admin/code/ModelAdmin.php
index db54dcb50..63426a0bf 100644
--- a/admin/code/ModelAdmin.php
+++ b/admin/code/ModelAdmin.php
@@ -366,7 +366,7 @@ abstract class ModelAdmin extends LeftAndMain {
 			'ModelName' => Convert::raw2att($modelName),
 			'Fields' => $specFields,
 			'Relations' => $specRelations,
-		))->renderWith('ModelAdmin_ImportSpec');
+		))->renderWith('Includes/ModelAdmin_ImportSpec');
 
 		$fields->push(new LiteralField("SpecFor{$modelName}", $specHTML));
 		$fields->push(
diff --git a/admin/templates/CMSBreadcrumbs.ss b/admin/templates/Includes/CMSBreadcrumbs.ss
similarity index 100%
rename from admin/templates/CMSBreadcrumbs.ss
rename to admin/templates/Includes/CMSBreadcrumbs.ss
diff --git a/admin/templates/CMSTabSet.ss b/admin/templates/forms/CMSTabSet.ss
similarity index 100%
rename from admin/templates/CMSTabSet.ss
rename to admin/templates/forms/CMSTabSet.ss
diff --git a/core/Core.php b/core/Core.php
index 66801e7dd..76e646012 100644
--- a/core/Core.php
+++ b/core/Core.php
@@ -77,8 +77,7 @@ require_once 'core/manifest/ConfigManifest.php';
 require_once 'core/manifest/ConfigStaticManifest.php';
 require_once 'core/manifest/ClassManifest.php';
 require_once 'core/manifest/ManifestFileFinder.php';
-require_once 'core/manifest/TemplateLoader.php';
-require_once 'core/manifest/TemplateManifest.php';
+require_once 'view/TemplateLoader.php';
 require_once 'core/manifest/TokenisedRegularExpression.php';
 require_once 'control/injector/Injector.php';
 
@@ -113,7 +112,7 @@ $configManifest = new SS_ConfigManifest(BASE_PATH, false, $flush);
 Config::inst()->pushConfigYamlManifest($configManifest);
 
 // Load template manifest
-SS_TemplateLoader::instance()->pushManifest(new SS_TemplateManifest(
+SilverStripe\View\TemplateLoader::instance()->addSet('$default', new SilverStripe\View\ThemeManifest(
 	BASE_PATH, project(), false, $flush
 ));
 
diff --git a/core/manifest/TemplateLoader.php b/core/manifest/TemplateLoader.php
deleted file mode 100644
index 5f9e7f58a..000000000
--- a/core/manifest/TemplateLoader.php
+++ /dev/null
@@ -1,87 +0,0 @@
-<?php
-/**
- * Handles finding templates from a stack of template manifest objects.
- *
- * @package framework
- * @subpackage manifest
- */
-class SS_TemplateLoader {
-
-	/**
-	 * @var SS_TemplateLoader
-	 */
-	private static $instance;
-
-	/**
-	 * @var SS_TemplateManifest[]
-	 */
-	protected $manifests = array();
-
-	/**
-	 * @return SS_TemplateLoader
-	 */
-	public static function instance() {
-		return self::$instance ? self::$instance : self::$instance = new self();
-	}
-
-	/**
-	 * Returns the currently active template manifest instance.
-	 *
-	 * @return SS_TemplateManifest
-	 */
-	public function getManifest() {
-		return $this->manifests[count($this->manifests) - 1];
-	}
-
-	/**
-	 * @param SS_TemplateManifest $manifest
-	 */
-	public function pushManifest(SS_TemplateManifest $manifest) {
-		$this->manifests[] = $manifest;
-	}
-
-	/**
-	 * @return SS_TemplateManifest
-	 */
-	public function popManifest() {
-		return array_pop($this->manifests);
-	}
-
-	/**
-	 * Attempts to find possible candidate templates from a set of template
-	 * names from modules, current theme directory and finally the application
-	 * folder.
-	 *
-	 * The template names can be passed in as plain strings, or be in the
-	 * format "type/name", where type is the type of template to search for
-	 * (e.g. Includes, Layout).
-	 *
-	 * @param  string|array $templates
-	 * @param  string $theme
-	 *
-	 * @return array
-	 */
-	public function findTemplates($templates, $theme = null) {
-		$result = array();
-
-		foreach ((array) $templates as $template) {
-			if (strpos($template, '/')) {
-				list($type, $template) = explode('/', $template, 2);
-			} else {
-				$type = null;
-			}
-
-			if ($found = $this->getManifest()->getCandidateTemplate($template, $theme)) {
-					if ($type && isset($found[$type])) {
-						$found = array(
-							'main' => $found[$type]
-						);
-					}
-					$result = array_merge($found, $result);
-				}
-			}
-
-		return $result;
-	}
-
-}
diff --git a/core/manifest/TemplateManifest.php b/core/manifest/TemplateManifest.php
deleted file mode 100644
index 4839a29a8..000000000
--- a/core/manifest/TemplateManifest.php
+++ /dev/null
@@ -1,271 +0,0 @@
-<?php
-/**
- * A class which builds a manifest of all templates present in a directory,
- * in both modules and themes.
- *
- * @package framework
- * @subpackage manifest
- */
-class SS_TemplateManifest {
-
-	const TEMPLATES_DIR = 'templates';
-
-	protected $base;
-	protected $tests;
-	protected $cache;
-	protected $cacheKey;
-	protected $project;
-	protected $inited;
-	protected $templates = array();
-
-	/**
-	 * Constructs a new template manifest. The manifest is not actually built
-	 * or loaded from cache until needed.
-	 *
-	 * @param string $base The base path.
-	 * @param string $project Path to application code
-	 *
-	 * @param bool $includeTests Include tests in the manifest.
-	 * @param bool $forceRegen Force the manifest to be regenerated.
-	 */
-	public function __construct($base, $project, $includeTests = false, $forceRegen = false) {
-		$this->base  = $base;
-		$this->tests = $includeTests;
-
-		$this->project = $project;
-
-		$cacheClass = defined('SS_MANIFESTCACHE') ? SS_MANIFESTCACHE : 'ManifestCache_File';
-
-		$this->cache = new $cacheClass('templatemanifest'.($includeTests ? '_tests' : ''));
-		$this->cacheKey = $this->getCacheKey($includeTests);
-
-		if ($forceRegen) {
-			$this->regenerate();
-		}
-	}
-
-	/**
-	 * @return string
-	 */
-	public function getBase() {
-		return $this->base;
-	}
-
-	/**
-	 * Generate a unique cache key to avoid manifest cache collisions.
-	 * We compartmentalise based on the base path, the given project, and whether
-	 * or not we intend to include tests.
-	 * @param boolean $includeTests
-	 * @return string
-	 */
-	public function getCacheKey($includeTests = false) {
-		return sha1(sprintf(
-			"manifest-%s-%s-%s",
-				$this->base,
-				$this->project,
-				(int) $includeTests // cast true to 1, false to 0
-			)
-		);
-	}
-
-	/**
-	 * Returns a map of all template information. The map is in the following
-	 * format:
-	 *
-	 * <code>
-	 *   array(
-	 *     'moduletemplate' => array(
-	 *       'main' => '/path/to/module/templates/Main.ss'
-	 *     ),
-	 *     'include' => array(
-	 *       'include' => '/path/to/module/templates/Includes/Include.ss'
-	 *     ),
-	 *     'page' => array(
-	 *       'themes' => array(
-	 *         'simple' => array(
-	 *           'main'   => '/path/to/theme/Page.ss'
-	 *           'Layout' => '/path/to/theme/Layout/Page.ss'
-	 *         )
-	 *       )
-	 *     )
-	 *   )
-	 * </code>
-	 *
-	 * @return array
-	 */
-	public function getTemplates() {
-		if (!$this->inited) {
-			$this->init();
-		}
-
-		return $this->templates;
-	}
-
-	/**
-	 * Returns a set of possible candidate templates that match a certain
-	 * template name.
-	 *
-	 * This is the same as extracting an individual array element from
-	 * {@link SS_TemplateManifest::getTemplates()}.
-	 *
-	 * @param  string $name
-	 * @return array
-	 */
-	public function getTemplate($name) {
-		if (!$this->inited) {
-			$this->init();
-		}
-
-		$name = strtolower($name);
-
-		if (array_key_exists($name, $this->templates)) {
-			return $this->templates[$name];
-		} else {
-			return array();
-		}
-	}
-
-	/**
-	 * Returns the correct candidate template. In order of importance, application
-	 * project code, current theme and finally modules.
-	 *
-	 * @param string $name
-	 * @param string $theme - theme name
-	 *
-	 * @return array
-	 */
-	public function getCandidateTemplate($name, $theme = null) {
-		$found = array();
-		$candidates = $this->getTemplate($name);
-
-		// theme overrides modules
-		if ($theme && isset($candidates['themes'][$theme])) {
-			$found = array_merge($candidates, $candidates['themes'][$theme]);
-		}
-		// project overrides theme
-		if ($this->project && isset($candidates[$this->project])) {
-			$found = array_merge($found, $candidates[$this->project]);
-		}
-
-		$found = ($found) ? $found : $candidates;
-
-		if (isset($found['themes'])) unset($found['themes']);
-		if (isset($found[$this->project])) unset($found[$this->project]);
-
-		return $found;
-	}
-
-	/**
-	 * Regenerates the manifest by scanning the base path.
-	 *
-	 * @param bool $cache
-	 */
-	public function regenerate($cache = true) {
-		$finder = new ManifestFileFinder();
-		$finder->setOptions(array(
-			'name_regex'     => '/\.ss$/',
-			'include_themes' => true,
-			'ignore_tests'  => !$this->tests,
-			'file_callback'  => array($this, 'handleFile')
-		));
-
-		$finder->find($this->base);
-
-		if ($cache) {
-			$this->cache->save($this->templates, $this->cacheKey);
-		}
-
-		$this->inited = true;
-	}
-
-	public function handleFile($basename, $pathname, $depth)
-	{
-		$projectFile = false;
-		$theme = null;
-
-		// Template in theme
-		if (preg_match(
-			'#'.preg_quote($this->base.'/'.THEMES_DIR).'/([^/_]+)(_[^/]+)?/(.*)$#',
-			$pathname,
-			$matches
-		)) {
-			$theme = $matches[1];
-			$relPath = $matches[3];
-
-		// Template in project
-		} elseif (preg_match(
-			'#'.preg_quote($this->base.'/'.$this->project).'/(.*)$#',
-			$pathname,
-			$matches
-		)) {
-			$projectFile = true;
-			$relPath = $matches[1];
-
-		// Template in module
-		} elseif (preg_match(
-			'#'.preg_quote($this->base).'/([^/]+)/(.*)$#',
-			$pathname,
-			$matches
-		)) {
-			$relPath = $matches[2];
-
-		} else {
-			throw new \LogicException("Can't determine meaning of path: $pathname");
-		}
-
-		// If a templates subfolder is used, ignore that
-		if (preg_match('#'.preg_quote(self::TEMPLATES_DIR).'/(.*)$#', $relPath, $matches)) {
-			$relPath = $matches[1];
-		}
-
-		// Layout and Content folders have special meaning
-		if (preg_match('#^(.*/)?(Layout|Content|Includes)/([^/]+)$#', $relPath, $matches)) {
-			$type = $matches[2];
-			$relPath = "$matches[1]$matches[3]";
-		} else {
-			$type = "main";
-		}
-
-		$name = strtolower(substr($relPath, 0, -3));
-		$name = str_replace('/', '\\', $name);
-
-		if ($theme) {
-			$this->templates[$name]['themes'][$theme][$type] = $pathname;
-		} else if ($projectFile) {
-			$this->templates[$name][$this->project][$type] = $pathname;
-		} else {
-			$this->templates[$name][$type] = $pathname;
-		}
-
-		// If we've found a template in a subdirectory, then allow its use for a non-namespaced class
-		// as well. This was a common SilverStripe 3 approach, where templates were placed into
-		// subfolders to suit the whim of the developer.
-		if (strpos($name, '\\') !== false) {
-			$name2 = substr($name, strrpos($name, '\\') + 1);
-			// In of these cases, the template will only be provided if it isn't already set. This
-			// matches SilverStripe 3 prioritisation.
-			if ($theme) {
-				if (!isset($this->templates[$name2]['themes'][$theme][$type])) {
-					$this->templates[$name2]['themes'][$theme][$type] = $pathname;
-				}
-			} else if ($projectFile) {
-				if (!isset($this->templates[$name2][$this->project][$type])) {
-					$this->templates[$name2][$this->project][$type] = $pathname;
-				}
-			} else {
-				if (!isset($this->templates[$name2][$type])) {
-					$this->templates[$name2][$type] = $pathname;
-				}
-			}
-		}
-	}
-
-	protected function init() {
-		if ($data = $this->cache->load($this->cacheKey)) {
-			$this->templates = $data;
-			$this->inited    = true;
-		} else {
-			$this->regenerate();
-		}
-	}
-}
diff --git a/dev/SapphireTest.php b/dev/SapphireTest.php
index b9fdb9c77..9a7f50e28 100644
--- a/dev/SapphireTest.php
+++ b/dev/SapphireTest.php
@@ -13,8 +13,8 @@ use SilverStripe\Security\Member;
 use SilverStripe\Security\Security;
 use SilverStripe\Security\Group;
 use SilverStripe\Security\Permission;
-
-
+use SilverStripe\View\TemplateLoader;
+use SilverStripe\View\ThemeManifest;
 
 /**
  * Test case class for the Sapphire framework.
@@ -848,7 +848,7 @@ class SapphireTest extends PHPUnit_Framework_TestCase {
 		SS_ClassLoader::instance()->pushManifest($classManifest, false);
 		SapphireTest::set_test_class_manifest($classManifest);
 
-		SS_TemplateLoader::instance()->pushManifest(new SS_TemplateManifest(
+		TemplateLoader::instance()->addSet('$default', new ThemeManifest(
 			BASE_PATH, project(), true, $flush
 		));
 
@@ -1054,22 +1054,15 @@ class SapphireTest extends PHPUnit_Framework_TestCase {
 	 */
 	protected function useTestTheme($themeBaseDir, $theme, $callback) {
 		Config::nest();
-		global $project;
 
-		$manifest = new SS_TemplateManifest($themeBaseDir, $project, true, true);
-
-		SS_TemplateLoader::instance()->pushManifest($manifest);
-
-		Config::inst()->update('SSViewer', 'theme', $theme);
+		if (strpos($themeBaseDir, BASE_PATH) === 0) $themeBaseDir = substr($themeBaseDir, strlen(BASE_PATH));
+		SSViewer::set_themes([$themeBaseDir.'/themes/'.$theme, '$default']);
 
 		$e = null;
 
 		try { $callback(); }
 		catch (Exception $e) { /* NOP for now, just save $e */ }
 
-		// Remove all the test themes we created
-		SS_TemplateLoader::instance()->popManifest();
-
 		Config::unnest();
 
 		if ($e) throw $e;
diff --git a/docs/en/04_Changelogs/4.0.0.md b/docs/en/04_Changelogs/4.0.0.md
index c91773d09..ea3d58239 100644
--- a/docs/en/04_Changelogs/4.0.0.md
+++ b/docs/en/04_Changelogs/4.0.0.md
@@ -395,6 +395,14 @@ all changed project files.
 This will resolve the majority of upgrading work, but for specific changes that will
 require manual intervention, please see the below upgrading notes.
 
+### Make sure templates are in correct locations
+
+Templates are now much more strict about their locations. You can no longer put a template in an arbitrary
+folder and have it be found. Case is now also checked on case-sensitive filesystems.
+
+Either include the folder in the template name (`renderWith('Field.ss')` => `renderWith('forms/Field.ss')`), move the 
+template into the correct directory, or both.
+
 ### Update code that uses SQLQuery
 
 Where your code once used SQLQuery you should now use SQLSelect in all cases, as this has been removed.
diff --git a/email/Email.php b/email/Email.php
index b35dcbabe..c0dbca55f 100644
--- a/email/Email.php
+++ b/email/Email.php
@@ -373,7 +373,7 @@ class Email extends ViewableData {
 				// Requery data so that updated versions of To, From, Subject, etc are included
 				$data = $this->templateData();
 
-				$template = new SSViewer($this->ss_template);
+				$template = new SSViewer('email/'.$this->ss_template);
 
 				if($template->exists()) {
 					$fullBody = $template->process($data);
diff --git a/filesystem/flysystem/ProtectedAssetAdapter.php b/filesystem/flysystem/ProtectedAssetAdapter.php
index 1dc91b200..2ca223f55 100644
--- a/filesystem/flysystem/ProtectedAssetAdapter.php
+++ b/filesystem/flysystem/ProtectedAssetAdapter.php
@@ -16,10 +16,10 @@ class ProtectedAssetAdapter extends AssetAdapter implements ProtectedAdapter {
 
     private static $server_configuration = array(
         'apache' => array(
-            '.htaccess' => "Protected_HTAccess"
+            '.htaccess' => "filesystem/Protected_HTAccess"
         ),
         'microsoft-iis' => array(
-            'web.config' => "Protected_WebConfig"
+            'web.config' => "filesystem/Protected_WebConfig"
         )
     );
 
diff --git a/filesystem/flysystem/PublicAssetAdapter.php b/filesystem/flysystem/PublicAssetAdapter.php
index e6e27f024..d425a7439 100644
--- a/filesystem/flysystem/PublicAssetAdapter.php
+++ b/filesystem/flysystem/PublicAssetAdapter.php
@@ -21,10 +21,10 @@ class PublicAssetAdapter extends AssetAdapter implements PublicAdapter {
 	 */
 	private static $server_configuration = array(
 		'apache' => array(
-			'.htaccess' => "Assets_HTAccess"
+			'.htaccess' => "filesystem/Assets_HTAccess"
 		),
 		'microsoft-iis' => array(
-			'web.config' => "Assets_WebConfig"
+			'web.config' => "filesystem/Assets_WebConfig"
 		)
 	);
 
diff --git a/forms/AssetField.php b/forms/AssetField.php
index 9e983606d..7cbc13e7a 100644
--- a/forms/AssetField.php
+++ b/forms/AssetField.php
@@ -48,7 +48,7 @@ class AssetField extends FileField {
 	 *
 	 * @var string
 	 */
-	protected $templateFileButtons = 'AssetField_FileButtons';
+	protected $templateFileButtons = 'Includes/AssetField_FileButtons';
 
 	/**
 	 * Parent data record. Will be infered from parent form or controller if blank. The destination
diff --git a/forms/Form.php b/forms/Form.php
index 7edee9dd3..5dd5e9d3e 100644
--- a/forms/Form.php
+++ b/forms/Form.php
@@ -1632,7 +1632,7 @@ class Form extends RequestHandler {
 	public function forTemplate() {
 		$return = $this->renderWith(array_merge(
 			(array)$this->getTemplate(),
-			array('Form')
+			array('Includes/Form')
 		));
 
 		// Now that we're rendered, clear message
diff --git a/forms/FormField.php b/forms/FormField.php
index 37e43bc35..62ffefe55 100644
--- a/forms/FormField.php
+++ b/forms/FormField.php
@@ -1051,7 +1051,7 @@ class FormField extends RequestHandler {
 		$matches = array();
 
 		foreach(array_reverse(ClassInfo::ancestry($this)) as $className) {
-			$matches[] = $className . $customTemplateSuffix;
+			$matches[] = 'forms/'. $className . $customTemplateSuffix;
 
 			if($className == "FormField") {
 				break;
@@ -1059,7 +1059,7 @@ class FormField extends RequestHandler {
 		}
 
 		if($customTemplate) {
-			array_unshift($matches, $customTemplate);
+			array_unshift($matches, 'forms/'.$customTemplate);
 		}
 
 		return $matches;
diff --git a/forms/MemberDatetimeOptionsetField.php b/forms/MemberDatetimeOptionsetField.php
index a3d456247..67f011ff1 100644
--- a/forms/MemberDatetimeOptionsetField.php
+++ b/forms/MemberDatetimeOptionsetField.php
@@ -44,6 +44,7 @@ class MemberDatetimeOptionsetField extends OptionsetField {
 			'Options' => new ArrayList($options)
 		));
 
+
 		return $this->customise($properties)->renderWith(
 			$this->getTemplates()
 		);
diff --git a/forms/UploadField.php b/forms/UploadField.php
index d0a582a8a..3f43f3f99 100644
--- a/forms/UploadField.php
+++ b/forms/UploadField.php
@@ -65,7 +65,7 @@ class UploadField extends FileField {
 	 *
 	 * @var string
 	 */
-	protected $templateFileButtons = 'UploadField_FileButtons';
+	protected $templateFileButtons = 'Includes/UploadField_FileButtons';
 
 	/**
 	 * Template to use for the edit form
diff --git a/forms/gridfield/GridFieldAddExistingAutocompleter.php b/forms/gridfield/GridFieldAddExistingAutocompleter.php
index 3796c1cd8..e9898d97c 100644
--- a/forms/gridfield/GridFieldAddExistingAutocompleter.php
+++ b/forms/gridfield/GridFieldAddExistingAutocompleter.php
@@ -131,7 +131,7 @@ class GridFieldAddExistingAutocompleter
 		}
 
 		return array(
-			$this->targetFragment => $forTemplate->renderWith($this->itemClass)
+			$this->targetFragment => $forTemplate->renderWith('Includes/'.$this->itemClass)
 		);
 	}
 
diff --git a/forms/gridfield/GridFieldAddNewButton.php b/forms/gridfield/GridFieldAddNewButton.php
index 4c63e455b..ca83deb05 100644
--- a/forms/gridfield/GridFieldAddNewButton.php
+++ b/forms/gridfield/GridFieldAddNewButton.php
@@ -44,7 +44,7 @@ class GridFieldAddNewButton implements GridField_HTMLProvider {
 		));
 
 		return array(
-			$this->targetFragment => $data->renderWith('GridFieldAddNewbutton'),
+			$this->targetFragment => $data->renderWith('Includes/GridFieldAddNewButton'),
 		);
 	}
 
diff --git a/forms/gridfield/GridFieldButtonRow.php b/forms/gridfield/GridFieldButtonRow.php
index 5acb8c82a..58feae9b4 100644
--- a/forms/gridfield/GridFieldButtonRow.php
+++ b/forms/gridfield/GridFieldButtonRow.php
@@ -27,7 +27,7 @@ class GridFieldButtonRow implements GridField_HTMLProvider {
 		));
 
 		return array(
-			$this->targetFragment => $data->renderWith('GridFieldButtonRow')
+			$this->targetFragment => $data->renderWith('Includes/GridFieldButtonRow')
 		);
 	}
 }
diff --git a/forms/gridfield/GridFieldDetailForm.php b/forms/gridfield/GridFieldDetailForm.php
index 8f16724e9..c7a4084a3 100644
--- a/forms/gridfield/GridFieldDetailForm.php
+++ b/forms/gridfield/GridFieldDetailForm.php
@@ -441,7 +441,7 @@ class GridFieldDetailForm_ItemRequest extends RequestHandler {
 			// Always show with base template (full width, no other panels),
 			// regardless of overloaded CMS controller templates.
 			// TODO Allow customization, e.g. to display an edit form alongside a search form from the CMS controller
-			$form->setTemplate('LeftAndMain_EditForm');
+			$form->setTemplate('Includes/LeftAndMain_EditForm');
 			$form->addExtraClass('cms-content cms-edit-form center');
 			$form->setAttribute('data-pjax-fragment', 'CurrentForm Content');
 			if($form->Fields()->hasTabset()) {
diff --git a/forms/gridfield/GridFieldEditButton.php b/forms/gridfield/GridFieldEditButton.php
index 8f2b6dc66..9801e3b3f 100644
--- a/forms/gridfield/GridFieldEditButton.php
+++ b/forms/gridfield/GridFieldEditButton.php
@@ -86,7 +86,7 @@ class GridFieldEditButton implements GridField_ColumnProvider {
 			'Link' => Controller::join_links($gridField->Link('item'), $record->ID, 'edit')
 		));
 
-		return $data->renderWith('GridFieldEditButton');
+		return $data->renderWith('Includes/GridFieldEditButton');
 	}
 
 	/**
diff --git a/forms/gridfield/GridFieldFilterHeader.php b/forms/gridfield/GridFieldFilterHeader.php
index 02798da23..471f99700 100755
--- a/forms/gridfield/GridFieldFilterHeader.php
+++ b/forms/gridfield/GridFieldFilterHeader.php
@@ -162,7 +162,7 @@ class GridFieldFilterHeader implements GridField_HTMLProvider, GridField_DataMan
 		}
 
 		return array(
-			'header' => $forTemplate->renderWith('GridFieldFilterHeader_Row'),
+			'header' => $forTemplate->renderWith('Includes/GridFieldFilterHeader_Row'),
 		);
 	}
 }
diff --git a/forms/gridfield/GridFieldFooter.php b/forms/gridfield/GridFieldFooter.php
index 1fba1c2a6..e360ded96 100644
--- a/forms/gridfield/GridFieldFooter.php
+++ b/forms/gridfield/GridFieldFooter.php
@@ -48,7 +48,7 @@ class GridFieldFooter implements GridField_HTMLProvider {
 
 		return array(
 			'footer' => $forTemplate->renderWith(
-				'GridFieldFooter',
+				'Includes/GridFieldFooter',
 				array(
 					'Colspan' => count($gridField->getColumns())
 				)
diff --git a/forms/gridfield/GridFieldLevelup.php b/forms/gridfield/GridFieldLevelup.php
index 34149217b..4894f1cbe 100644
--- a/forms/gridfield/GridFieldLevelup.php
+++ b/forms/gridfield/GridFieldLevelup.php
@@ -66,7 +66,7 @@ class GridFieldLevelup extends Object implements GridField_HTMLProvider {
 			));
 
 			return array(
-				'before' => $forTemplate->renderWith('GridFieldLevelup'),
+				'before' => $forTemplate->renderWith('Includes/GridFieldLevelup'),
 			);
 		}
 	}
diff --git a/forms/gridfield/GridFieldPageCount.php b/forms/gridfield/GridFieldPageCount.php
index e7175a71a..380dc2490 100755
--- a/forms/gridfield/GridFieldPageCount.php
+++ b/forms/gridfield/GridFieldPageCount.php
@@ -67,7 +67,7 @@ class GridFieldPageCount implements GridField_HTMLProvider {
 		$paginator = $this->getPaginator($gridField);
 		if ($paginator && ($forTemplate = $paginator->getTemplateParameters($gridField))) {
 			return array(
-				$this->targetFragment => $forTemplate->renderWith($this->itemClass)
+				$this->targetFragment => $forTemplate->renderWith('Includes/'.$this->itemClass)
 			);
 		}
 	}
diff --git a/forms/gridfield/GridFieldPaginator.php b/forms/gridfield/GridFieldPaginator.php
index 5f298f43e..332746384 100755
--- a/forms/gridfield/GridFieldPaginator.php
+++ b/forms/gridfield/GridFieldPaginator.php
@@ -259,7 +259,7 @@ class GridFieldPaginator implements GridField_HTMLProvider, GridField_DataManipu
 		$forTemplate = $this->getTemplateParameters($gridField);
 		if($forTemplate) {
 			return array(
-				'footer' => $forTemplate->renderWith($this->itemClass,
+				'footer' => $forTemplate->renderWith('Includes/'.$this->itemClass,
 					array('Colspan'=>count($gridField->getColumns())))
 			);
 		}
diff --git a/forms/gridfield/GridFieldSortableHeader.php b/forms/gridfield/GridFieldSortableHeader.php
index a85a3c956..963e4c37c 100644
--- a/forms/gridfield/GridFieldSortableHeader.php
+++ b/forms/gridfield/GridFieldSortableHeader.php
@@ -164,7 +164,7 @@ class GridFieldSortableHeader implements GridField_HTMLProvider, GridField_DataM
 		}
 
 		return array(
-			'header' => $forTemplate->renderWith('GridFieldSortableHeader_Row'),
+			'header' => $forTemplate->renderWith('Includes/GridFieldSortableHeader_Row'),
 		);
 	}
 
diff --git a/forms/gridfield/GridFieldToolbarHeader.php b/forms/gridfield/GridFieldToolbarHeader.php
index f4cab23b7..3f8296d98 100644
--- a/forms/gridfield/GridFieldToolbarHeader.php
+++ b/forms/gridfield/GridFieldToolbarHeader.php
@@ -13,7 +13,7 @@ class GridFieldToolbarHeader implements GridField_HTMLProvider {
 
 	public function getHTMLFragments( $gridField) {
 		return array(
-			'header' => $gridField->renderWith('GridFieldToolbarHeader')
+			'header' => $gridField->renderWith('Includes/GridFieldToolbarHeader')
 		);
 	}
 }
diff --git a/forms/gridfield/GridFieldViewButton.php b/forms/gridfield/GridFieldViewButton.php
index c18190e3a..c65773376 100644
--- a/forms/gridfield/GridFieldViewButton.php
+++ b/forms/gridfield/GridFieldViewButton.php
@@ -22,7 +22,7 @@ class GridFieldViewButton implements GridField_ColumnProvider {
 			$data = new ArrayData(array(
 				'Link' => Controller::join_links($field->Link('item'), $record->ID, 'view')
 			));
-			return $data->renderWith('GridFieldViewButton');
+			return $data->renderWith('Includes/GridFieldViewButton');
 		}
 	}
 
diff --git a/forms/htmleditor/HTMLEditorField.php b/forms/htmleditor/HTMLEditorField.php
index 8a6eca7bb..f7ab9ccde 100644
--- a/forms/htmleditor/HTMLEditorField.php
+++ b/forms/htmleditor/HTMLEditorField.php
@@ -181,7 +181,7 @@ class HTMLEditorField_Toolbar extends RequestHandler {
 	/**
 	 * @var string
 	 */
-	protected $templateViewFile = 'HTMLEditorField_viewfile';
+	protected $templateViewFile = 'Includes/HTMLEditorField_viewfile';
 
 	protected $controller, $name;
 
diff --git a/forms/htmleditor/TinyMCEConfig.php b/forms/htmleditor/TinyMCEConfig.php
index fea517b8e..423ee7ca2 100644
--- a/forms/htmleditor/TinyMCEConfig.php
+++ b/forms/htmleditor/TinyMCEConfig.php
@@ -1,5 +1,7 @@
 <?php
 
+use SilverStripe\View\TemplateLoader;
+
 /**
  * Default configuration for HtmlEditor specific to tinymce
  */
@@ -419,13 +421,18 @@ class TinyMCEConfig extends HTMLEditorConfig {
 			Director::absoluteBaseURL(),
 			FRAMEWORK_ADMIN_DIR . '/client/dist/styles/editor.css'
 		);
-		if($theme = SSViewer::get_theme_folder()) {
-			$editorDir = $theme . '/css/editor.css';
+
+		foreach(SSViewer::get_themes() as $theme) {
+			$path = TemplateLoader::instance()->getPath($theme);
+			$editorDir = $path . '/css/editor.css';;
+
 			if(file_exists(BASE_PATH . '/' . $editorDir)) {
 				$editor[] = Controller::join_links(
 					Director::absoluteBaseURL(),
 					$editorDir
 				);
+
+				break;
 			}
 		}
 		return $editor;
diff --git a/templates/AssetField.ss b/templates/forms/AssetField.ss
similarity index 100%
rename from templates/AssetField.ss
rename to templates/forms/AssetField.ss
diff --git a/templates/AssetUploadField.ss b/templates/forms/AssetUploadField.ss
similarity index 100%
rename from templates/AssetUploadField.ss
rename to templates/forms/AssetUploadField.ss
diff --git a/templates/HTMLEditorField_UploadField.ss b/templates/forms/HTMLEditorField_UploadField.ss
similarity index 100%
rename from templates/HTMLEditorField_UploadField.ss
rename to templates/forms/HTMLEditorField_UploadField.ss
diff --git a/templates/UploadField.ss b/templates/forms/UploadField.ss
similarity index 100%
rename from templates/UploadField.ss
rename to templates/forms/UploadField.ss
diff --git a/tests/core/manifest/TemplateLoaderTest.php b/tests/core/manifest/TemplateLoaderTest.php
index 3bffdd623..ebcb7cb0b 100644
--- a/tests/core/manifest/TemplateLoaderTest.php
+++ b/tests/core/manifest/TemplateLoaderTest.php
@@ -1,6 +1,10 @@
 <?php
+
+use SilverStripe\View\TemplateLoader;
+use SilverStripe\View\ThemeManifest;
+
 /**
- * Tests for the {@link SS_TemplateLoader} class.
+ * Tests for the {@link TemplateLoader} class.
  *
  * @package framework
  * @subpackage tests
@@ -16,162 +20,82 @@ class TemplateLoaderTest extends SapphireTest {
 	 */
 	public function setUp() {
 		parent::setUp();
+		// Fake project root
 		$this->base = dirname(__FILE__) . '/fixtures/templatemanifest';
-		$this->manifest = new SS_TemplateManifest($this->base, 'myproject', false, true);
-		$this->loader = new SS_TemplateLoader();
-		$this->refreshLoader();
+		// New ThemeManifest for that root
+		$this->manifest = new \SilverStripe\View\ThemeManifest($this->base, 'myproject', false, true);
+		// New Loader for that root
+		$this->loader = new \SilverStripe\View\TemplateLoader($this->base);
+		$this->loader->addSet('$default', $this->manifest);
 	}
 
 	/**
 	 * Test that 'main' and 'Layout' templates are loaded from module
 	 */
 	public function testFindTemplatesInModule() {
-		$expect = array(
-			'main'   => "$this->base/module/templates/Page.ss",
-			'Layout' => "$this->base/module/templates/Layout/Page.ss"
+		$this->assertEquals(
+			"$this->base/module/templates/Page.ss",
+			$this->loader->findTemplate('Page', ['$default'])
+		);
+
+		$this->assertEquals(
+			"$this->base/module/templates/Layout/Page.ss",
+			$this->loader->findTemplate(['type' => 'Layout', 'Page'], ['$default'])
 		);
-		$this->assertEquals($expect, $this->loader->findTemplates('Page'));
-		$this->assertEquals($expect, $this->loader->findTemplates('PAGE'));
-		$this->assertEquals($expect, $this->loader->findTemplates(array('Foo', 'Page')));
 	}
 
 	/**
 	 * Test that 'main' and 'Layout' templates are loaded from set theme
 	 */
 	public function testFindTemplatesInTheme() {
-		$expect = array(
-			'main'   => "$this->base/themes/theme/templates/Page.ss",
-			'Layout' => "$this->base/themes/theme/templates/Layout/Page.ss"
+		$this->assertEquals(
+			"$this->base/themes/theme/templates/Page.ss",
+			$this->loader->findTemplate('Page', ['theme'])
+		);
+
+		$this->assertEquals(
+			"$this->base/themes/theme/templates/Layout/Page.ss",
+			$this->loader->findTemplate(['type' => 'Layout', 'Page'], ['theme'])
 		);
-		$this->assertEquals($expect, $this->loader->findTemplates('Page', 'theme'));
-		$this->assertEquals($expect, $this->loader->findTemplates('PAGE', 'theme'));
-		$this->assertEquals($expect, $this->loader->findTemplates(array('Foo', 'Page'), 'theme'));
 	}
 
 	/**
 	 * Test that 'main' and 'Layout' templates are loaded from project without a set theme
 	 */
 	public function testFindTemplatesInApplication() {
+		// TODO: replace with one that doesn't create temporary files (so bad)
 		$templates = array(
 			$this->base . '/myproject/templates/Page.ss',
 			$this->base . '/myproject/templates/Layout/Page.ss'
 		);
 		$this->createTestTemplates($templates);
-		$this->refreshLoader();
 
-		$expect = array(
-			'main'   => "$this->base/myproject/templates/Page.ss",
-			'Layout' => "$this->base/myproject/templates/Layout/Page.ss"
+		$this->assertEquals(
+			"$this->base/myproject/templates/Page.ss",
+			$this->loader->findTemplate('Page', ['$default'])
+		);
+
+		$this->assertEquals(
+			"$this->base/myproject/templates/Layout/Page.ss",
+			$this->loader->findTemplate(['type' => 'Layout', 'Page'], ['$default'])
 		);
-		$this->assertEquals($expect, $this->loader->findTemplates('Page'));
-		$this->assertEquals($expect, $this->loader->findTemplates('PAGE'));
-		$this->assertEquals($expect, $this->loader->findTemplates(array('Foo', 'Page')));
 
 		$this->removeTestTemplates($templates);
 	}
 
-	/**
-	 * Test that 'Layout' template is loaded from module
-	 */
-	public function testFindTemplatesInModuleLayout() {
-		$expect = array(
-			'main' => "$this->base/module/templates/Layout/Page.ss"
-		);
-		$this->assertEquals($expect, $this->loader->findTemplates('Layout/Page'));
-	}
-
-	/**
-	 * Test that 'Layout' template is loaded from theme
-	 */
-	public function testFindTemplatesInThemeLayout() {
-		$expect = array(
-			'main' => "$this->base/themes/theme/templates/Layout/Page.ss"
-		);
-		$this->assertEquals($expect, $this->loader->findTemplates('Layout/Page', 'theme'));
-	}
-
 	/**
 	 * Test that 'main' template is found in theme and 'Layout' is found in module
 	 */
 	public function testFindTemplatesMainThemeLayoutModule() {
-		$expect = array(
-			'main'   => "$this->base/themes/theme/templates/CustomThemePage.ss",
-			'Layout' => "$this->base/module/templates/Layout/CustomThemePage.ss"
+		$this->assertEquals(
+			"$this->base/themes/theme/templates/CustomThemePage.ss",
+			$this->loader->findTemplate('CustomThemePage', ['theme', '$default'])
 		);
-		$this->assertEquals($expect, $this->loader->findTemplates(array('CustomThemePage', 'Page'), 'theme'));
-	}
 
-	/**
-	 * Test that project template overrides module template of same name
-	 */
-	public function testFindTemplatesApplicationOverridesModule() {
-		$expect = array(
-			'main'   => "$this->base/myproject/templates/CustomTemplate.ss"
+		$this->assertEquals(
+			"$this->base/module/templates/Layout/CustomThemePage.ss",
+			$this->loader->findTemplate(['type' => 'Layout', 'CustomThemePage'], ['theme', '$default'])
 		);
-		$this->assertEquals($expect, $this->loader->findTemplates('CustomTemplate'));
-	}
-
-	/**
-	 * Test that project templates overrides theme templates
-	 */
-	public function testFindTemplatesApplicationOverridesTheme() {
-		$templates = array(
-			$this->base . '/myproject/templates/Page.ss',
-			$this->base . '/myproject/templates/Layout/Page.ss'
-		);
-		$this->createTestTemplates($templates);
-		$this->refreshLoader();
-
-		$expect = array(
-			'main'   => "$this->base/myproject/templates/Page.ss",
-			'Layout' => "$this->base/myproject/templates/Layout/Page.ss"
-		);
-		$this->assertEquals($expect, $this->loader->findTemplates('Page'), 'theme');
-
-		$this->removeTestTemplates($templates);
-	}
-
-	/**
-	 * Test that project 'Layout' template overrides theme 'Layout' template
-	 */
-	public function testFindTemplatesApplicationLayoutOverridesThemeLayout() {
-		$templates = array(
-			$this->base . '/myproject/templates/Layout/Page.ss'
-		);
-		$this->createTestTemplates($templates);
-		$this->refreshLoader();
-
-		$expect = array(
-			'main' => "$this->base/themes/theme/templates/Page.ss",
-			'Layout' => "$this->base/myproject/templates/Layout/Page.ss"
-		);
-		$this->assertEquals($expect, $this->loader->findTemplates('Page', 'theme'));
-
-		$this->removeTestTemplates($templates);
-	}
-
-	/**
-	 * Test that project 'main' template overrides theme 'main' template
-	 */
-	public function testFindTemplatesApplicationMainOverridesThemeMain() {
-		$templates = array(
-			$this->base . '/myproject/templates/Page.ss'
-		);
-		$this->createTestTemplates($templates);
-		$this->refreshLoader();
-
-		$expect = array(
-			'main' => "$this->base/myproject/templates/Page.ss",
-			'Layout' => "$this->base/themes/theme/templates/Layout/Page.ss"
-		);
-		$this->assertEquals($expect, $this->loader->findTemplates('Page', 'theme'));
-
-		$this->removeTestTemplates($templates);
-	}
-
-	protected function refreshLoader() {
-		$this->manifest->regenerate(false);
-		$this->loader->pushManifest($this->manifest);
 	}
 
 	protected function createTestTemplates($templates) {
diff --git a/tests/core/manifest/TemplateManifestTest.php b/tests/core/manifest/TemplateManifestTest.php
deleted file mode 100644
index 61e9af45c..000000000
--- a/tests/core/manifest/TemplateManifestTest.php
+++ /dev/null
@@ -1,141 +0,0 @@
-<?php
-/**
- * Tests for the template manifest.
- *
- * @package framework
- * @subpackage tests
- */
-class TemplateManifestTest extends SapphireTest {
-
-	protected $base;
-	protected $manifest;
-	protected $manifestTests;
-
-	public function setUp() {
-		parent::setUp();
-
-		$this->base = dirname(__FILE__) . '/fixtures/templatemanifest';
-		$this->manifest      = new SS_TemplateManifest($this->base, 'myproject');
-		$this->manifestTests = new SS_TemplateManifest($this->base, 'myproject', true);
-
-		$this->manifest->regenerate(false);
-		$this->manifestTests->regenerate(false);
-	}
-
-	public function testGetTemplates() {
-		$expect = array(
-			'root' => array(
-				'main' => "{$this->base}/module/Root.ss"
-			),
-			'page' => array(
-				'main'   => "{$this->base}/module/templates/Page.ss",
-				'Layout' => "{$this->base}/module/templates/Layout/Page.ss",
-				'themes' => array('theme' => array(
-					'main'   => "{$this->base}/themes/theme/templates/Page.ss",
-					'Layout' => "{$this->base}/themes/theme/templates/Layout/Page.ss"
-				))
-			),
-			'custompage' => array(
-				'Layout' => "{$this->base}/module/templates/Layout/CustomPage.ss"
-			),
-			'customtemplate' => array(
-				'main' => "{$this->base}/module/templates/CustomTemplate.ss",
-				'myproject' => array(
-					'main' => "{$this->base}/myproject/templates/CustomTemplate.ss"
-				)
-			),
-			'subfolder' => array(
-				'main' => "{$this->base}/module/subfolder/templates/Subfolder.ss"
-			),
-			'customthemepage' => array (
-				'Layout' => "{$this->base}/module/templates/Layout/CustomThemePage.ss",
-				'themes' =>
-				array(
-					'theme' => array('main' => "{$this->base}/themes/theme/templates/CustomThemePage.ss",)
-				)
-			),
-			'mynamespace\myclass' => array(
-				'main' => "{$this->base}/module/templates/MyNamespace/MyClass.ss",
-				'Layout' => "{$this->base}/module/templates/MyNamespace/Layout/MyClass.ss",
-				'themes' => array(
-					'theme' => array(
-						'main' => "{$this->base}/themes/theme/templates/MyNamespace/MyClass.ss",
-					)
-				),
-			),
-			'mynamespace\mysubnamespace\mysubclass' => array(
-				'main' => "{$this->base}/module/templates/MyNamespace/MySubnamespace/MySubclass.ss",
-			),
-			'myclass' => array(
-				'main' => "{$this->base}/module/templates/MyNamespace/MyClass.ss",
-				'Layout' => "{$this->base}/module/templates/MyNamespace/Layout/MyClass.ss",
-				'themes' => array(
-					'theme' => array(
-						'main' => "{$this->base}/themes/theme/templates/MyNamespace/MyClass.ss",
-					)
-				),
-			),
-			'mysubclass' => array(
-				'main' => "{$this->base}/module/templates/MyNamespace/MySubnamespace/MySubclass.ss",
-			),
-			'include' => array('themes' => array(
-				'theme' => array(
-					'Includes' => "{$this->base}/themes/theme/templates/Includes/Include.ss"
-				)
-			))
-		);
-
-		$expectTests = $expect;
-		$expectTests['test'] = array(
-			'main' => "{$this->base}/module/tests/templates/Test.ss"
-		);
-
-		$manifest      = $this->manifest->getTemplates();
-		$manifestTests = $this->manifestTests->getTemplates();
-
-		ksort($expect);
-		ksort($expectTests);
-		ksort($manifest);
-		ksort($manifestTests);
-
-		$this->assertEquals(
-			$expect, $manifest,
-			'All templates are correctly loaded in the manifest.'
-		);
-
-		$this->assertEquals(
-			$expectTests, $manifestTests,
-			'The test manifest is the same, but includes test templates.'
-		);
-	}
-
-	public function testGetTemplate() {
-		$expectPage = array(
-			'main'   => "{$this->base}/module/templates/Page.ss",
-			'Layout' => "{$this->base}/module/templates/Layout/Page.ss",
-			'themes' => array('theme' => array(
-				'main'   => "{$this->base}/themes/theme/templates/Page.ss",
-				'Layout' => "{$this->base}/themes/theme/templates/Layout/Page.ss"
-			))
-		);
-
-		$expectTests = array(
-			'main' => "{$this->base}/module/tests/templates/Test.ss"
-		);
-
-		$this->assertEquals($expectPage, $this->manifest->getTemplate('Page'));
-		$this->assertEquals($expectPage, $this->manifest->getTemplate('PAGE'));
-		$this->assertEquals($expectPage, $this->manifestTests->getTemplate('Page'));
-		$this->assertEquals($expectPage, $this->manifestTests->getTemplate('PAGE'));
-
-		$this->assertEquals(array(), $this->manifest->getTemplate('Test'));
-		$this->assertEquals($expectTests, $this->manifestTests->getTemplate('Test'));
-
-		$this->assertEquals(array(
-			'main' => "{$this->base}/module/templates/CustomTemplate.ss",
-			'myproject' => array(
-				'main' => "{$this->base}/myproject/templates/CustomTemplate.ss"
-		)), $this->manifestTests->getTemplate('CustomTemplate'));
-	}
-
-}
diff --git a/tests/forms/MemberDatetimeOptionsetFieldTest.php b/tests/forms/MemberDatetimeOptionsetFieldTest.php
index 8d25221dd..7aa127726 100644
--- a/tests/forms/MemberDatetimeOptionsetFieldTest.php
+++ b/tests/forms/MemberDatetimeOptionsetFieldTest.php
@@ -110,7 +110,7 @@ class MemberDatetimeOptionsetFieldTest extends SapphireTest {
 		$field->setDescription('Test description');
 		$this->assertEquals('Test description', $field->getDescription());
 
-		$field->setDescriptionTemplate('MemberDatetimeOptionsetField_description_time');
+		$field->setDescriptionTemplate('forms/MemberDatetimeOptionsetField_description_time');
 		$this->assertNotEmpty($field->getDescription());
 		$this->assertNotEquals('Test description', $field->getDescription());
 	}
diff --git a/tests/i18n/i18nSSLegacyAdapterTest.php b/tests/i18n/i18nSSLegacyAdapterTest.php
index 520eec3f9..475cba780 100644
--- a/tests/i18n/i18nSSLegacyAdapterTest.php
+++ b/tests/i18n/i18nSSLegacyAdapterTest.php
@@ -1,9 +1,11 @@
 <?php
+
+use SilverStripe\View\TemplateLoader;
+
 /**
  * @package framework
  * @subpackage i18n
  */
-
 class i18nSSLegacyAdapterTest extends SapphireTest {
 
 	public function setUp() {
@@ -14,10 +16,10 @@ class i18nSSLegacyAdapterTest extends SapphireTest {
 		Filesystem::makeFolder($this->alternateBaseSavePath);
 		Config::inst()->update('Director', 'alternate_base_folder', $this->alternateBasePath);
 
-		// Push a template loader running from the fake webroot onto the stack.
-		$templateManifest = new SS_TemplateManifest($this->alternateBasePath, null, false, true);
-		$templateManifest->regenerate(false);
-		SS_TemplateLoader::instance()->pushManifest($templateManifest);
+		// Replace old template loader with new one with alternate base path
+		$this->_oldLoader = TemplateLoader::instance();
+		TemplateLoader::set_instance(new TemplateLoader($this->alternateBasePath));
+
 		$this->_oldTheme = Config::inst()->get('SSViewer', 'theme');
 		Config::inst()->update('SSViewer', 'theme', 'testtheme1');
 
@@ -40,7 +42,7 @@ class i18nSSLegacyAdapterTest extends SapphireTest {
 	}
 
 	public function tearDown() {
-		SS_TemplateLoader::instance()->popManifest();
+		TemplateLoader::set_instance($this->_oldLoader);
 		SS_ClassLoader::instance()->popManifest();
 		i18n::set_locale($this->originalLocale);
 		Config::inst()->update('Director', 'alternate_base_folder', null);
diff --git a/tests/i18n/i18nTest.php b/tests/i18n/i18nTest.php
index 3c0fb6209..3f774f5b2 100644
--- a/tests/i18n/i18nTest.php
+++ b/tests/i18n/i18nTest.php
@@ -1,6 +1,9 @@
 <?php
 
 use SilverStripe\ORM\DataObject;
+use SilverStripe\View\TemplateLoader;
+use SilverStripe\View\ThemeManifest;
+
 require_once 'Zend/Translate.php';
 
 /**
@@ -35,10 +38,13 @@ class i18nTest extends SapphireTest {
 		FileSystem::makeFolder($this->alternateBaseSavePath);
 		Config::inst()->update('Director', 'alternate_base_folder', $this->alternateBasePath);
 
-		// Push a template loader running from the fake webroot onto the stack.
-		$templateManifest = new SS_TemplateManifest($this->alternateBasePath, null, false, true);
-		$templateManifest->regenerate(false);
-		SS_TemplateLoader::instance()->pushManifest($templateManifest);
+		// Replace old template loader with new one with alternate base path
+		$this->_oldLoader = TemplateLoader::instance();
+		TemplateLoader::set_instance($loader = new TemplateLoader($this->alternateBasePath));
+		$loader->addSet('$default', new ThemeManifest(
+			$this->alternateBasePath, project(), false, true
+		));
+
 		$this->_oldTheme = Config::inst()->get('SSViewer', 'theme');
 		Config::inst()->update('SSViewer', 'theme', 'testtheme1');
 
@@ -58,7 +64,7 @@ class i18nTest extends SapphireTest {
 	}
 
 	public function tearDown() {
-		SS_TemplateLoader::instance()->popManifest();
+		TemplateLoader::set_instance($this->_oldLoader);
 		i18n::set_locale($this->originalLocale);
 		Config::inst()->update('Director', 'alternate_base_folder', null);
 		Config::inst()->update('SSViewer', 'theme', $this->_oldTheme);
diff --git a/tests/i18n/i18nTextCollectorTest.php b/tests/i18n/i18nTextCollectorTest.php
index e6da0eda2..ca599b452 100644
--- a/tests/i18n/i18nTextCollectorTest.php
+++ b/tests/i18n/i18nTextCollectorTest.php
@@ -1,4 +1,7 @@
 <?php
+
+use SilverStripe\View\TemplateLoader;
+
 /**
  * @package framework
  * @subpackage tests
@@ -34,13 +37,13 @@ class i18nTextCollectorTest extends SapphireTest {
 			$this->alternateBasePath, false, true, false
 		);
 
-		$manifest = new SS_TemplateManifest($this->alternateBasePath, null, false, true);
-		$manifest->regenerate(false);
-		SS_TemplateLoader::instance()->pushManifest($manifest);
+		// Replace old template loader with new one with alternate base path
+		$this->_oldLoader = TemplateLoader::instance();
+		TemplateLoader::set_instance(new TemplateLoader($this->alternateBasePath));
 	}
 
 	public function tearDown() {
-		SS_TemplateLoader::instance()->popManifest();
+		TemplateLoader::set_instance($this->_oldLoader);
 		// Pop if added during testing
 		if(SS_ClassLoader::instance()->getManifest() === $this->manifest) {
 			SS_ClassLoader::instance()->popManifest();
diff --git a/tests/templates/SSViewerTestComments/SSViewerTestCommentsInclude.ss b/tests/templates/Includes/SSViewerTestCommentsInclude.ss
similarity index 100%
rename from tests/templates/SSViewerTestComments/SSViewerTestCommentsInclude.ss
rename to tests/templates/Includes/SSViewerTestCommentsInclude.ss
diff --git a/tests/templates/SSViewerTestIncludeObjectArguments.ss b/tests/templates/Includes/SSViewerTestIncludeObjectArguments.ss
similarity index 100%
rename from tests/templates/SSViewerTestIncludeObjectArguments.ss
rename to tests/templates/Includes/SSViewerTestIncludeObjectArguments.ss
diff --git a/tests/templates/SSViewerTestIncludeScopeInheritanceInclude.ss b/tests/templates/Includes/SSViewerTestIncludeScopeInheritanceInclude.ss
similarity index 100%
rename from tests/templates/SSViewerTestIncludeScopeInheritanceInclude.ss
rename to tests/templates/Includes/SSViewerTestIncludeScopeInheritanceInclude.ss
diff --git a/tests/templates/SSViewerTestIncludeScopeInheritanceWithArgsInLoop.ss b/tests/templates/Includes/SSViewerTestIncludeScopeInheritanceWithArgsInLoop.ss
similarity index 100%
rename from tests/templates/SSViewerTestIncludeScopeInheritanceWithArgsInLoop.ss
rename to tests/templates/Includes/SSViewerTestIncludeScopeInheritanceWithArgsInLoop.ss
diff --git a/tests/templates/SSViewerTestIncludeScopeInheritanceWithArgsInNestedWith.ss b/tests/templates/Includes/SSViewerTestIncludeScopeInheritanceWithArgsInNestedWith.ss
similarity index 100%
rename from tests/templates/SSViewerTestIncludeScopeInheritanceWithArgsInNestedWith.ss
rename to tests/templates/Includes/SSViewerTestIncludeScopeInheritanceWithArgsInNestedWith.ss
diff --git a/tests/templates/SSViewerTestIncludeScopeInheritanceWithArgsInWith.ss b/tests/templates/Includes/SSViewerTestIncludeScopeInheritanceWithArgsInWith.ss
similarity index 100%
rename from tests/templates/SSViewerTestIncludeScopeInheritanceWithArgsInWith.ss
rename to tests/templates/Includes/SSViewerTestIncludeScopeInheritanceWithArgsInWith.ss
diff --git a/tests/templates/SSViewerTestIncludeScopeInheritanceWithUpAndTop.ss b/tests/templates/Includes/SSViewerTestIncludeScopeInheritanceWithUpAndTop.ss
similarity index 100%
rename from tests/templates/SSViewerTestIncludeScopeInheritanceWithUpAndTop.ss
rename to tests/templates/Includes/SSViewerTestIncludeScopeInheritanceWithUpAndTop.ss
diff --git a/tests/templates/SSViewerTestIncludeWIthArguments.ss b/tests/templates/Includes/SSViewerTestIncludeWithArguments.ss
similarity index 100%
rename from tests/templates/SSViewerTestIncludeWIthArguments.ss
rename to tests/templates/Includes/SSViewerTestIncludeWithArguments.ss
diff --git a/tests/templates/SSViewerTestProcessHead.ss b/tests/templates/Includes/SSViewerTestProcessHead.ss
similarity index 100%
rename from tests/templates/SSViewerTestProcessHead.ss
rename to tests/templates/Includes/SSViewerTestProcessHead.ss
diff --git a/tests/templates/SSViewerTestRecursiveInclude.ss b/tests/templates/Includes/SSViewerTestRecursiveInclude.ss
similarity index 100%
rename from tests/templates/SSViewerTestRecursiveInclude.ss
rename to tests/templates/Includes/SSViewerTestRecursiveInclude.ss
diff --git a/tests/templates/Namespace/NamespaceInclude.ss b/tests/templates/Namespace/Includes/NamespaceInclude.ss
similarity index 100%
rename from tests/templates/Namespace/NamespaceInclude.ss
rename to tests/templates/Namespace/Includes/NamespaceInclude.ss
diff --git a/tests/templates/SSViewerTestProcess.ss b/tests/templates/SSViewerTestProcess.ss
index 8ab505478..60561e017 100644
--- a/tests/templates/SSViewerTestProcess.ss
+++ b/tests/templates/SSViewerTestProcess.ss
@@ -2,6 +2,5 @@
 	<% include SSViewerTestProcessHead %>
 
 	<body>
-		<% include SSViewerTestCommentsWithInclude %>
 	</body>
 </html>
diff --git a/tests/view/SSViewerTest.php b/tests/view/SSViewerTest.php
index 87f6ae127..c6602e861 100644
--- a/tests/view/SSViewerTest.php
+++ b/tests/view/SSViewerTest.php
@@ -759,17 +759,11 @@ after')
 			$this->render('tests:( <% include Namespace/NamespaceInclude %> )', $data),
 			'Forward slashes work for namespace references in includes'
 		);
-
-		$this->assertEquals(
-			"tests:( NamespaceInclude\n )",
-			$this->render('tests:( <% include NamespaceInclude %> )', $data),
-			'Namespace can be missed for a namespaed include'
-		);
 	}
 
 
 	public function testRecursiveInclude() {
-		$view = new SSViewer(array('SSViewerTestRecursiveInclude'));
+		$view = new SSViewer(array('Includes/SSViewerTestRecursiveInclude'));
 
 		$data = new ArrayData(array(
 			'Title' => 'A',
@@ -1160,21 +1154,21 @@ after')
 		$this->useTestTheme(dirname(__FILE__), 'layouttest', function() use ($self) {
 			// Test passing a string
 			$templates = SSViewer::get_templates_by_class(
-				'TestNamespace\SSViewerTest_Controller',
+				'TestNamespace\SSViewerTestModel_Controller',
 				'',
 				'Controller'
 			);
 			$self->assertEquals([
-				'TestNamespace\SSViewerTest_Controller',
+				'TestNamespace\SSViewerTestModel_Controller',
     			'Controller',
 			], $templates);
 
 			// Test to ensure we're stopping at the base class.
-			$templates = SSViewer::get_templates_by_class('TestNamespace\SSViewerTest_Controller', '', 'TestNamespace\SSViewerTest_Controller');
+			$templates = SSViewer::get_templates_by_class('TestNamespace\SSViewerTestModel_Controller', '', 'TestNamespace\SSViewerTestModel_Controller');
 			$self->assertCount(1, $templates);
 
 			// Make sure we can filter our templates by suffix.
-			$templates = SSViewer::get_templates_by_class('SSViewerTest', '_Controller');
+			$templates = SSViewer::get_templates_by_class('TestNamespace\SSViewerTestModel', '_Controller');
 			$self->assertCount(1, $templates);
 
 			// Let's throw something random in there.
@@ -1183,38 +1177,6 @@ after')
 		});
 	}
 
-	/**
-	 * @covers SSViewer::get_themes()
-	 */
-	public function testThemeRetrieval() {
-		$ds = DIRECTORY_SEPARATOR;
-		$testThemeBaseDir = TEMP_FOLDER . $ds . 'test-themes';
-
-		if(file_exists($testThemeBaseDir)) Filesystem::removeFolder($testThemeBaseDir);
-
-		mkdir($testThemeBaseDir);
-		mkdir($testThemeBaseDir . $ds . 'blackcandy');
-		mkdir($testThemeBaseDir . $ds . 'blackcandy_blog');
-		mkdir($testThemeBaseDir . $ds . 'darkshades');
-		mkdir($testThemeBaseDir . $ds . 'darkshades_blog');
-
-		$this->assertEquals(array(
-			'blackcandy' => 'blackcandy',
-			'darkshades' => 'darkshades'
-		), SSViewer::get_themes($testThemeBaseDir), 'Our test theme directory contains 2 themes');
-
-		$this->assertEquals(array(
-			'blackcandy' => 'blackcandy',
-			'blackcandy_blog' => 'blackcandy_blog',
-			'darkshades' => 'darkshades',
-			'darkshades_blog' => 'darkshades_blog'
-		), SSViewer::get_themes($testThemeBaseDir, true),
-			'Our test theme directory contains 2 themes and 2 sub-themes');
-
-		// Remove all the test themes we created
-		Filesystem::removeFolder($testThemeBaseDir);
-	}
-
 	public function testRewriteHashlinks() {
 		$orig = Config::inst()->get('SSViewer', 'rewrite_hash_links');
 		Config::inst()->update('SSViewer', 'rewrite_hash_links', true);
@@ -1327,6 +1289,7 @@ EOC;
 		$origEnv = Config::inst()->get('Director', 'environment_type');
 		Config::inst()->update('Director', 'environment_type', 'dev');
 		Config::inst()->update('SSViewer', 'source_file_comments', true);
+		$i = FRAMEWORK_PATH . '/tests/templates/Includes';
 		$f = FRAMEWORK_PATH . '/tests/templates/SSViewerTestComments';
 		$templates = array(
 			array(
@@ -1398,16 +1361,16 @@ EOC;
 				"<!-- template $f/SSViewerTestCommentsWithInclude.ss -->"
 					. "<div class='typography'>"
 					. "<!-- include 'SSViewerTestCommentsInclude' -->"
-					. "<!-- template $f/SSViewerTestCommentsInclude.ss -->"
+					. "<!-- template $i/SSViewerTestCommentsInclude.ss -->"
 					. "Included"
-					. "<!-- end template $f/SSViewerTestCommentsInclude.ss -->"
+					. "<!-- end template $i/SSViewerTestCommentsInclude.ss -->"
 					. "<!-- end include 'SSViewerTestCommentsInclude' -->"
 					. "</div>"
 					. "<!-- end template $f/SSViewerTestCommentsWithInclude.ss -->",
 			),
 		);
 		foreach ($templates as $template) {
-			$this->_renderWithSourceFileComments($template['name'], $template['expected']);
+			$this->_renderWithSourceFileComments('SSViewerTestComments/'.$template['name'], $template['expected']);
 		}
 		Config::inst()->update('SSViewer', 'source_file_comments', false);
 		Config::inst()->update('Director', 'environment_type', $origEnv);
diff --git a/tests/view/TestNamespace/SSViewerTest_Controller.php b/tests/view/TestNamespace/SSViewerTest_Controller.php
index 6814768b6..882c2d56a 100644
--- a/tests/view/TestNamespace/SSViewerTest_Controller.php
+++ b/tests/view/TestNamespace/SSViewerTest_Controller.php
@@ -2,7 +2,12 @@
 
 namespace TestNamespace;
 
-class SSViewerTest_Controller extends \Controller
-{
+use SilverStripe\ORM\DataObject;
+
+class SSViewerTestModel extends DataObject {
+
+}
+
+class SSViewerTestModel_Controller extends \Controller {
 
 }
diff --git a/tests/view/themes/layouttest/Controller.ss b/tests/view/themes/layouttest/templates/Controller.ss
similarity index 100%
rename from tests/view/themes/layouttest/Controller.ss
rename to tests/view/themes/layouttest/templates/Controller.ss
diff --git a/tests/view/themes/layouttest/Layout/Page.ss b/tests/view/themes/layouttest/templates/Layout/Page.ss
similarity index 100%
rename from tests/view/themes/layouttest/Layout/Page.ss
rename to tests/view/themes/layouttest/templates/Layout/Page.ss
diff --git a/tests/view/themes/layouttest/Layout/Shortcodes.ss b/tests/view/themes/layouttest/templates/Layout/Shortcodes.ss
similarity index 100%
rename from tests/view/themes/layouttest/Layout/Shortcodes.ss
rename to tests/view/themes/layouttest/templates/Layout/Shortcodes.ss
diff --git a/tests/view/themes/layouttest/Page.ss b/tests/view/themes/layouttest/templates/Page.ss
similarity index 100%
rename from tests/view/themes/layouttest/Page.ss
rename to tests/view/themes/layouttest/templates/Page.ss
diff --git a/tests/view/themes/layouttest/TestNamespace/SSViewerTest_Controller.ss b/tests/view/themes/layouttest/templates/TestNamespace/SSViewerTestModel_Controller.ss
similarity index 100%
rename from tests/view/themes/layouttest/TestNamespace/SSViewerTest_Controller.ss
rename to tests/view/themes/layouttest/templates/TestNamespace/SSViewerTestModel_Controller.ss
diff --git a/view/Requirements.php b/view/Requirements.php
index a3bf19e96..f4c778e27 100644
--- a/view/Requirements.php
+++ b/view/Requirements.php
@@ -1,6 +1,7 @@
 <?php
 
 use SilverStripe\Filesystem\Storage\GeneratedAssetHandler;
+use SilverStripe\View\TemplateLoader;
 
 /**
  * Requirements tracker for JavaScript and CSS.
@@ -818,7 +819,7 @@ class Requirements_Backend
 	public function javascript($file, $options = array()) {
 	    // make sure that async/defer is set if it is set once even if file is included multiple times
         $async = (
-            isset($options['async']) && isset($options['async']) == true  
+            isset($options['async']) && isset($options['async']) == true
             || (
                 isset($this->javascript[$file])
                 && isset($this->javascript[$file]['async'])
@@ -842,7 +843,7 @@ class Requirements_Backend
 		if(isset($options['provides'])) {
 			$this->providedJavascript[$file] = array_values($options['provides']);
 	    }
-	
+
 	}
 
 	/**
@@ -1798,21 +1799,27 @@ class Requirements_Backend
 	 *                       (e.g. 'screen,projector')
 	 */
 	public function themedCSS($name, $module = null, $media = null) {
-		$theme = SSViewer::get_theme_folder();
-		$project = project();
-		$absbase = BASE_PATH . DIRECTORY_SEPARATOR;
-		$abstheme = $absbase . $theme;
-		$absproject = $absbase . $project;
 		$css = "/css/$name.css";
 
+		$project = project();
+		$absbase = BASE_PATH . DIRECTORY_SEPARATOR;
+		$absproject = $absbase . $project;
+
 		if(file_exists($absproject . $css)) {
-			$this->css($project . $css, $media);
-		} elseif($module && file_exists($abstheme . '_' . $module.$css)) {
-			$this->css($theme . '_' . $module . $css, $media);
-		} elseif(file_exists($abstheme . $css)) {
-			$this->css($theme . $css, $media);
-		} elseif($module) {
-			$this->css($module . $css, $media);
+			return $this->css($project . $css, $media);
+		}
+
+		foreach(SSViewer::get_themes() as $theme) {
+			$path = TemplateLoader::instance()->getPath($theme);
+			$abspath = BASE_PATH . '/' . $path;
+
+			if(file_exists($abspath . $css)) {
+				return $this->css($path . $css, $media);
+			}
+		}
+
+		if($module) {
+			return $this->css($module . $css, $media);
 		}
 	}
 
diff --git a/view/SSTemplateParser.php b/view/SSTemplateParser.php
index cc48950c1..ae681bfd8 100644
--- a/view/SSTemplateParser.php
+++ b/view/SSTemplateParser.php
@@ -3382,7 +3382,7 @@ class SSTemplateParser extends Parser implements TemplateParser {
 		$template = $res['template'];
 		$arguments = $res['arguments'];
 
-		$res['php'] = '$val .= SSViewer::execute_template('.$template.', $scope->getItem(), array(' .
+		$res['php'] = '$val .= SSViewer::execute_template(["type" => "Includes", '.$template.'], $scope->getItem(), array(' .
 			implode(',', $arguments)."), \$scope);\n";
 
 		if($this->includeDebuggingComments) { // Add include filename comments on dev sites
diff --git a/view/SSTemplateParser.php.inc b/view/SSTemplateParser.php.inc
index bc0b57d68..cad6e3fd3 100644
--- a/view/SSTemplateParser.php.inc
+++ b/view/SSTemplateParser.php.inc
@@ -830,7 +830,7 @@ class SSTemplateParser extends Parser implements TemplateParser {
 		$template = $res['template'];
 		$arguments = $res['arguments'];
 
-		$res['php'] = '$val .= SSViewer::execute_template('.$template.', $scope->getItem(), array(' .
+		$res['php'] = '$val .= SSViewer::execute_template(["type" => "Includes", '.$template.'], $scope->getItem(), array(' .
 			implode(',', $arguments)."), \$scope);\n";
 
 		if($this->includeDebuggingComments) { // Add include filename comments on dev sites
diff --git a/view/SSViewer.php b/view/SSViewer.php
index 3ce381ebe..7f771f2fa 100644
--- a/view/SSViewer.php
+++ b/view/SSViewer.php
@@ -3,6 +3,7 @@
 use SilverStripe\ORM\FieldType\DBField;
 use SilverStripe\ORM\FieldType\DBHTMLText;
 use SilverStripe\Security\Permission;
+use SilverStripe\View\TemplateLoader;
 
 /**
  * This tracks the current scope for an SSViewer instance. It has three goals:
@@ -723,10 +724,19 @@ class SSViewer implements Flushable {
 	}
 
 	/**
-	 * @var array $chosenTemplates Associative array for the different
-	 * template containers: "main" and "Layout". Values are absolute file paths to *.ss files.
+	 * @var array $templates List of templates to select from
 	 */
-	private $chosenTemplates = array();
+	private $templates = null;
+
+	/**
+	 * @var string $chosen Absolute path to chosen template file
+	 */
+	private $chosen = null;
+
+	/**
+	 * @var array Templates to use when looking up 'Layout' or 'Content'
+	 */
+	private $subTemplates = null;
 
 	/**
 	 * @var boolean
@@ -735,9 +745,17 @@ class SSViewer implements Flushable {
 
 	/**
 	 * @config
-	 * @var string The used "theme", which usually consists of templates, images and stylesheets.
+	 * @var string A list (highest priority first) of themes to use
 	 * Only used when {@link $theme_enabled} is set to TRUE.
 	 */
+	private static $themes = [];
+
+	/**
+	 * @deprecated 4.0..5.0
+	 * @config
+	 * @var string The used "theme", which usually consists of templates, images and stylesheets.
+	 * Only used when {@link $theme_enabled} is set to TRUE, and $themes is empty
+	 */
 	private static $theme = null;
 
 	/**
@@ -791,65 +809,33 @@ class SSViewer implements Flushable {
 		return $viewer;
 	}
 
+	public static function set_themes($themes = []) {
+		Config::inst()->remove('SSViewer', 'themes');
+		Config::inst()->update('SSViewer', 'themes', $themes);
+	}
+
+	public static function add_themes($themes = []) {
+		Config::inst()->update('SSViewer', 'themes', $themes);
+	}
+
+	public static function get_themes() {
+		$res = ['$default'];
+
+		if (Config::inst()->get('SSViewer', 'theme_enabled')) {
+			if ($list = Config::inst()->get('SSViewer', 'themes')) $res = $list;
+			elseif ($theme = Config::inst()->get('SSViewer', 'theme')) $res = [$theme, '$default'];
+		}
+
+		return $res;
+	}
+
 	/**
 	 * @deprecated 4.0 Use the "SSViewer.theme" config setting instead
 	 * @param string $theme The "base theme" name (without underscores).
 	 */
 	public static function set_theme($theme) {
-		Deprecation::notice('4.0', 'Use the "SSViewer.theme" config setting instead');
-		Config::inst()->update('SSViewer', 'theme', $theme);
-	}
-
-	/**
-	 * @deprecated 4.0 Use the "SSViewer.theme" config setting instead
-	 * @return string
-	 */
-	public static function current_theme() {
-		Deprecation::notice('4.0', 'Use the "SSViewer.theme" config setting instead');
-		return Config::inst()->get('SSViewer', 'theme');
-	}
-
-	/**
-	 * Returns the path to the theme folder
-	 *
-	 * @return string
-	 */
-	public static function get_theme_folder() {
-		$theme = Config::inst()->get('SSViewer', 'theme');
-		return $theme ? THEMES_DIR . "/" . $theme : project();
-	}
-
-	/**
-	 * Returns an array of theme names present in a directory.
-	 *
-	 * @param  string $path
-	 * @param  bool   $subthemes Include subthemes (default false).
-	 * @return array
-	 */
-	public static function get_themes($path = null, $subthemes = false) {
-		$path   = rtrim($path ? $path : THEMES_PATH, '/');
-		$themes = array();
-
-		if (!is_dir($path)) return $themes;
-
-		foreach (scandir($path) as $item) {
-			if ($item[0] != '.' && is_dir("$path/$item")) {
-				if ($subthemes || strpos($item, '_') === false) {
-					$themes[$item] = $item;
-				}
-			}
-		}
-
-		return $themes;
-	}
-
-	/**
-	 * @deprecated since version 4.0
-	 * @return string
-	 */
-	public static function current_custom_theme(){
-		Deprecation::notice('4.0', 'Use the "SSViewer.theme" and "SSViewer.theme_enabled" config settings instead');
-		return Config::inst()->get('SSViewer', 'theme_enabled') ? Config::inst()->get('SSViewer', 'theme') : null;
+		Deprecation::notice('4.0', 'Use the "SSViewer#set_themes" instead');
+		self::set_themes([$theme]);
 	}
 
 	/**
@@ -873,6 +859,7 @@ class SSViewer implements Flushable {
 		foreach($classes as $class) {
 			$template = $class . $suffix;
 			if(SSViewer::hasTemplate($template)) $templates[] = $template;
+			elseif(SSViewer::hasTemplate('Includes/'.$template)) $templates[] = 'Includes/'.$template;
 
 			// If the class is "Page_Controller", look for Page.ss
 			if(stripos($class,'_controller') !== false) {
@@ -893,38 +880,34 @@ class SSViewer implements Flushable {
 	 *  array('MySpecificPage', 'MyPage', 'Page')
 	 *  </code>
 	 */
-	public function __construct($templateList, TemplateParser $parser = null) {
+	public function __construct($templates, TemplateParser $parser = null) {
 		if ($parser) {
 			$this->setParser($parser);
 		}
 
-		if(!is_array($templateList) && substr((string) $templateList,-3) == '.ss') {
-			$this->chosenTemplates['main'] = $templateList;
-		} else {
-			if(Config::inst()->get('SSViewer', 'theme_enabled')) {
-				$theme = Config::inst()->get('SSViewer', 'theme');
-			} else {
-				$theme = null;
-			}
-			$this->chosenTemplates = SS_TemplateLoader::instance()->findTemplates(
-				$templateList, $theme
-			);
-		}
+		$this->setTemplate($templates);
 
-		if(!$this->chosenTemplates) {
-			$templateList = (is_array($templateList)) ? $templateList : array($templateList);
+		if(!$this->chosen) {
+			$message = 'None of the following templates could be found: ';
+			$message .= print_r($templates, true);
 
-			$message = 'None of the following templates could be found';
-			if(!$theme) {
+			$themes = self::get_themes();
+			if(!$themes) {
 				$message .= ' (no theme in use)';
 			} else {
-				$message .= ' in theme "' . $theme . '"';
+				$message .= ' in themes "' . print_r($themes, true) . '"';
 			}
 
-			user_error($message . ': ' . implode(".ss, ", $templateList) . ".ss", E_USER_WARNING);
+			user_error($message, E_USER_WARNING);
 		}
 	}
 
+	public function setTemplate($templates) {
+		$this->templates = $templates;
+		$this->chosen = TemplateLoader::instance()->findTemplate($templates, self::get_themes());
+		$this->subTemplates = [];
+	}
+
 	/**
 	 * Set the template parser that will be used in template generation
 	 * @param \TemplateParser $parser
@@ -954,19 +937,7 @@ class SSViewer implements Flushable {
 	 * @return boolean
 	 */
 	public static function hasTemplate($templates) {
-		$manifest = SS_TemplateLoader::instance()->getManifest();
-
-		if(Config::inst()->get('SSViewer', 'theme_enabled')) {
-			$theme = Config::inst()->get('SSViewer', 'theme');
-		} else {
-			$theme = null;
-		}
-
-		foreach ((array) $templates as $template) {
-			if ($manifest->getCandidateTemplate($template, $theme)) return true;
-		}
-
-		return false;
+		return (bool)TemplateLoader::instance()->findTemplate($templates, self::get_themes());
 	}
 
 	/**
@@ -1033,7 +1004,7 @@ class SSViewer implements Flushable {
 	}
 
 	public function exists() {
-		return $this->chosenTemplates;
+		return $this->chosen;
 	}
 
 	/**
@@ -1043,21 +1014,7 @@ class SSViewer implements Flushable {
 	 * @return string Full system path to a template file
 	 */
 	public static function getTemplateFileByType($identifier, $type) {
-		$loader = SS_TemplateLoader::instance();
-		if(Config::inst()->get('SSViewer', 'theme_enabled')) {
-			$theme = Config::inst()->get('SSViewer', 'theme');
-		} else {
-			$theme = null;
-		}
-		$found  = $loader->findTemplates("$type/$identifier", $theme);
-
-		if (isset($found['main'])) {
-			return $found['main'];
-		}
-		else if (!empty($found)) {
-			$founds = array_values($found);
-			return $founds[0];
-		}
+		return TemplateLoader::instance()->findTemplate(['type' => $type, $identifier], self::get_themes());
 	}
 
 	/**
@@ -1192,13 +1149,7 @@ class SSViewer implements Flushable {
 	public function process($item, $arguments = null, $inheritedScope = null) {
 		SSViewer::$topLevel[] = $item;
 
-		if(isset($this->chosenTemplates['main'])) {
-			$template = $this->chosenTemplates['main'];
-		} else {
-			$keys = array_keys($this->chosenTemplates);
-			$key = reset($keys);
-			$template = $this->chosenTemplates[$key];
-		}
+		$template = $this->chosen;
 
 		$cacheFile = TEMP_FOLDER . "/.cache"
 			. str_replace(array('\\','/',':'), '.', Director::makeRelative(realpath($template)));
@@ -1218,14 +1169,27 @@ class SSViewer implements Flushable {
 		// Makes the rendered sub-templates available on the parent item,
 		// through $Content and $Layout placeholders.
 		foreach(array('Content', 'Layout') as $subtemplate) {
-			if(isset($this->chosenTemplates[$subtemplate])) {
+			$sub = null;
+			if(isset($this->subTemplates[$subtemplate])) {
+				$sub = $this->subTemplates[$subtemplate];
+			}
+			elseif(!is_array($this->templates)) {
+				$sub = ['type' => $subtemplate, $this->templates];
+			}
+			elseif(!array_key_exists('type', $this->templates) || !$this->templates['type']) {
+				$sub = array_merge($this->templates, ['type' => $subtemplate]);
+			}
+
+			if ($sub) {
 				$subtemplateViewer = clone $this;
 				// Disable requirements - this will be handled by the parent template
 				$subtemplateViewer->includeRequirements(false);
-				// The subtemplate is the only file we want to process, so set it as the "main" template file
-				$subtemplateViewer->chosenTemplates = array('main' => $this->chosenTemplates[$subtemplate]);
+				// Select the right template
+				$subtemplateViewer->setTemplate($sub);
 
-				$underlay[$subtemplate] = $subtemplateViewer->process($item, $arguments);
+				if ($subtemplateViewer->exists()) {
+					$underlay[$subtemplate] = $subtemplateViewer->process($item, $arguments);
+				}
 			}
 		}
 
@@ -1301,7 +1265,7 @@ class SSViewer implements Flushable {
 	 * 'Content' & 'Layout', and will have to contain 'main'
 	 */
 	public function templates() {
-		return $this->chosenTemplates;
+		return array_merge(['main' => $this->chosen], $this->subTemplates);
 	}
 
 	/**
@@ -1309,7 +1273,8 @@ class SSViewer implements Flushable {
 	 * @param string $file Full system path to the template file
 	 */
 	public function setTemplateFile($type, $file) {
-		$this->chosenTemplates[$type] = $file;
+		if (!$type || $type == 'main') $this->chosen = $file;
+		else $this->subTemplates[$type] = $file;
 	}
 
 	/**
diff --git a/view/TemplateLoader.php b/view/TemplateLoader.php
new file mode 100644
index 000000000..8a7a58695
--- /dev/null
+++ b/view/TemplateLoader.php
@@ -0,0 +1,118 @@
+<?php
+
+namespace SilverStripe\View;
+
+/**
+ * Handles finding templates from a stack of template manifest objects.
+ *
+ * @package framework
+ * @subpackage view
+ */
+class TemplateLoader {
+
+	/**
+	 * @var TemplateLoader
+	 */
+	private static $instance;
+
+	protected $base;
+
+	protected $sets = [];
+
+	public static function instance() {
+		return self::$instance ? self::$instance : self::$instance = new self();
+	}
+
+	public static function set_instance(TemplateLoader $instance) {
+		self::$instance = $instance;
+	}
+
+	public function __construct($base = null) {
+		$this->base = $base ? $base : BASE_PATH;
+	}
+
+	public function addSet($set, $manifest) {
+		$this->sets[$set] = $manifest;
+	}
+
+	public function getPath($identifier) {
+		$slashPos = strpos($identifier, '/');
+
+		// If identifier starts with "/", it's a path from root
+		if ($slashPos === 0) {
+			return substr($identifier, 1);
+		}
+		// Otherwise if there is a "/", identifier is a vendor'ed module
+		elseif ($slashPos !== false) {
+			$parts = explode(':', $identifier, 2);
+
+			list($vendor, $module) = explode('/', $parts[0], 2);
+			$theme = count($parts) > 1 ? $parts[1] : '';
+
+			$path = $module . ($theme ? '/themes/'.$theme : '');
+
+			// Right now we require $module to be a silverstripe module (in root) or theme (in themes dir)
+			// If both exist, we prefer theme
+			if (is_dir(THEMES_PATH . '/' .$path)) {
+				return THEMES_DIR . '/' . $path;
+			}
+			else {
+				return $path;
+			}
+		}
+		// Otherwise it's a (deprecated) old-style "theme" identifier
+		else {
+			return THEMES_DIR.'/'.$identifier;
+		}
+	}
+
+	/**
+	 * Attempts to find possible candidate templates from a set of template
+	 * names from modules, current theme directory and finally the application
+	 * folder.
+	 *
+	 * The template names can be passed in as plain strings, or be in the
+	 * format "type/name", where type is the type of template to search for
+	 * (e.g. Includes, Layout).
+	 *
+	 * @param  string|array $templates
+	 * @param  string $theme
+	 *
+	 * @return array
+	 */
+	public function findTemplate($template, $themes = []) {
+
+		if(is_array($template)) {
+			$type = array_key_exists('type', $template) ? $template['type'] : '';
+			$templateList = array_key_exists('templates', $template) ? $template['templates'] : $template;
+		}
+		else {
+			$type = '';
+			$templateList = array($template);
+		}
+
+		if(count($templateList) == 1 && substr($templateList[0], -3) == '.ss') {
+			return $templateList[0];
+		}
+
+		foreach($templateList as $i => $template) {
+			$template = str_replace('\\', '/', $template);
+			$parts = explode('/', $template);
+
+			$tail = array_pop($parts);
+			$head = implode('/', $parts);
+
+			foreach($themes as $themename) {
+				$subthemes = isset($this->sets[$themename]) ? $this->sets[$themename]->getThemes() : [$themename];
+
+				foreach($subthemes as $theme) {
+					$themePath = $this->base . '/' . $this->getPath($theme);
+
+					$path = $themePath . '/templates/' . implode('/', array_filter([$head, $type, $tail])) . '.ss';
+					if (file_exists($path)) return $path;
+				}
+			}
+		}
+	}
+
+}
diff --git a/view/ThemeManifest.php b/view/ThemeManifest.php
new file mode 100644
index 000000000..1e17bedf0
--- /dev/null
+++ b/view/ThemeManifest.php
@@ -0,0 +1,140 @@
+<?php
+
+namespace SilverStripe\View;
+
+use \ManifestFileFinder;
+
+/**
+ * A class which builds a manifest of all themes (which is really just a directory called "templates")
+ *
+ * @package framework
+ * @subpackage manifest
+ */
+class ThemeManifest {
+
+	const TEMPLATES_DIR = 'templates';
+
+	protected $base;
+	protected $tests;
+	protected $project;
+
+	protected $cache;
+	protected $cacheKey;
+
+	protected $themes = null;
+
+	/**
+	 * Constructs a new template manifest. The manifest is not actually built
+	 * or loaded from cache until needed.
+	 *
+	 * @param string $base The base path.
+	 * @param string $project Path to application code
+	 *
+	 * @param bool $includeTests Include tests in the manifest.
+	 * @param bool $forceRegen Force the manifest to be regenerated.
+	 */
+	public function __construct($base, $project, $includeTests = false, $forceRegen = false) {
+		$this->base  = $base;
+		$this->tests = $includeTests;
+
+		$this->project = $project;
+
+		$cacheClass = defined('SS_MANIFESTCACHE') ? SS_MANIFESTCACHE : 'ManifestCache_File';
+
+		$this->cache = new $cacheClass('thememanifest'.($includeTests ? '_tests' : ''));
+		$this->cacheKey = $this->getCacheKey();
+
+		if ($forceRegen) {
+			$this->regenerate();
+		}
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getBase() {
+		return $this->base;
+	}
+
+	/**
+	 * Generate a unique cache key to avoid manifest cache collisions.
+	 * We compartmentalise based on the base path, the given project, and whether
+	 * or not we intend to include tests.
+	 * @return string
+	 */
+	public function getCacheKey() {
+		return sha1(sprintf(
+			"manifest-%s-%s-%u",
+			$this->base,
+			$this->project,
+			$this->tests
+		));
+	}
+
+	/**
+	 * Returns a map of all themes information. The map is in the following format:
+	 *
+	 * <code>
+	 *   [
+	 *     'mysite',
+	 *     'framework',
+	 *     'framework/admin'
+	 *   ]
+	 * </code>
+	 *
+	 * @return array
+	 */
+	public function getThemes() {
+		if ($this->themes === null) $this->init();
+		return $this->themes;
+	}
+
+	/**
+	 * Regenerates the manifest by scanning the base path.
+	 *
+	 * @param bool $cache
+	 */
+	public function regenerate($cache = true) {
+		$finder = new ManifestFileFinder();
+		$finder->setOptions(array(
+			'include_themes' => false,
+			'ignore_tests'  => !$this->tests,
+			'dir_callback'  => array($this, 'handleDirectory')
+		));
+
+		$this->themes = [];
+		$finder->find($this->base);
+
+		if ($cache) {
+			$this->cache->save($this->themes, $this->cacheKey);
+		}
+	}
+
+	public function handleDirectory($basename, $pathname, $depth)
+	{
+		if ($basename == self::TEMPLATES_DIR) {
+			// We only want part of the full path, so split into directories
+			$parts = explode('/', $pathname);
+			// Take the end (the part relative to base), except the very last directory
+			$themeParts = array_slice($parts, -$depth, $depth-1);
+			// Then join again
+			$path = '/'.implode('/', $themeParts);
+
+			// If this is in the project, add to beginning of list. Else add to end.
+			if ($themeParts[0] == $this->project) {
+				array_unshift($this->themes, $path);
+			}
+			else {
+				array_push($this->themes, $path);
+			}
+		}
+	}
+
+	protected function init() {
+		if ($data = $this->cache->load($this->cacheKey)) {
+			$this->themes = $data;
+		} else {
+			$this->regenerate();
+		}
+	}
+}