diff --git a/_config.php b/_config.php
index 6dae167..32ae9cf 100644
--- a/_config.php
+++ b/_config.php
@@ -1,5 +1,6 @@
 <?php
 define('DMS_DIR', 'dms');
+if (!file_exists(BASE_PATH . DIRECTORY_SEPARATOR . DMS_DIR)) user_error("DMS directory named incorrectly. Please install the DMS module into a folder named: ".DMS_DIR);
 
 Object::add_extension('SiteTree','DMSSiteTreeExtension');
 Object::add_extension('HtmlEditorField_Toolbar','DocumentHtmlEditorFieldToolbar');
@@ -7,4 +8,10 @@ CMSMenu::remove_menu_item('DMSDocumentAddController');
 
 ShortcodeParser::get('default')->register('dms_document_link', array('DMSDocument_Controller', 'dms_link_shortcode_handler'));
 
-if (!file_exists(BASE_PATH . DIRECTORY_SEPARATOR . DMS_DIR)) user_error("DMS directory named incorrectly. Please install the DMS module into a folder named: ".DMS_DIR);
\ No newline at end of file
+DMSDocument_versions::$enable_versions = true;
+
+if (DMSDocument_versions::$enable_versions) {
+	//using the same db relations for the versioned documents, as for the actual documents
+	Config::inst()->update('DMSDocument_versions', 'db', DMSDocument::$db);
+}
+
diff --git a/code/DMSDocument.php b/code/DMSDocument.php
index 15a170a..6b1c062 100755
--- a/code/DMSDocument.php
+++ b/code/DMSDocument.php
@@ -365,7 +365,8 @@ class DMSDocument extends DataObject implements DMSDocumentInterface {
 	 * @return DataList List of Document objects
 	 */
 	function getVersions() {
-		// TODO: Implement getVersions() method.
+		if (!DMSDocument_versions::$enable_versions) user_error("DMSDocument versions are disabled",E_USER_WARNING);
+		return DMSDocument_versions::get_versions($this);
 	}
 
 	/**
@@ -405,10 +406,22 @@ class DMSDocument extends DataObject implements DMSDocumentInterface {
 
 		$this->removeAllPages();
 
+		//get rid of any versions have saved for this DMSDocument, too
+		if (DMSDocument_versions::$enable_versions) {
+			$versions = $this->getVersions();
+			if ($versions->Count() > 0) {
+				foreach($versions as $v) {
+					$v->delete();
+				}
+			}
+		}
+
 		//delete the dataobject
 		parent::delete();
 	}
 
+
+
 	/**
 	 * Relate an existing file on the filesystem to the document.
 	 * Copies the file to the new destination, as defined in {@link get_DMS_path()}.
@@ -427,6 +440,12 @@ class DMSDocument extends DataObject implements DMSDocumentInterface {
 
 		//copy the file into place
 		$fromPath = BASE_PATH . DIRECTORY_SEPARATOR . $filePath;
+
+		//version the existing file (copy it to a new "very specific" filename
+		if (DMSDocument_versions::$enable_versions) {
+			DMSDocument_versions::create_version($this);
+		}
+
 		copy($fromPath, $toPath);   //this will overwrite the existing file (if present)
 
 		//write the filename of the stored document
@@ -510,6 +529,9 @@ class DMSDocument extends DataObject implements DMSDocumentInterface {
 
 		$fields = new FieldList();  //don't use the automatic scaffolding, it is slow and unnecessary here
 
+		$extraTasks = '';   //additional text to inject into the list of tasks at the bottom of a DMSDocument CMSfield
+		$extraFields = FormField::create('Empty');
+
 		//get list of shortcode page relations
 		$relationFinder = new ShortCodeRelationFinder();
 		$relationList = $relationFinder->getList($this->ID);
@@ -554,7 +576,6 @@ class DMSDocument extends DataObject implements DMSDocumentInterface {
 			$gridFieldConfig
 		);
 
-
 		$referencesGrid = GridField::create(
 			'References',
 			_t('DMSDocument.RelatedReferences', 'Related References'),
@@ -562,13 +583,35 @@ class DMSDocument extends DataObject implements DMSDocumentInterface {
 			$gridFieldConfig
 		);
 
+		if (DMSDocument_versions::$enable_versions) {
+			$versionsGridFieldConfig = GridFieldConfig::create()->addComponents(
+				new GridFieldToolbarHeader(),
+				new GridFieldSortableHeader(),
+				new GridFieldDataColumns(),
+				new GridFieldPaginator(30)
+			);
+			$versionsGridFieldConfig->getComponentByType('GridFieldDataColumns')->setDisplayFields(Config::inst()->get('DMSDocument_versions', 'display_fields'))
+									->setFieldCasting(array('LastChanged'=>"Datetime->Ago"))
+						 			->setFieldFormatting(array('FilenameWithoutID'=>'<a target=\'_blank\' class=\'file-url\' href=\'$Link\'>$FilenameWithoutID</a>'));
+
+			$versionsGrid =  GridField::create(
+				'Versions',
+				_t('DMSDocument.Versions', 'Versions'),
+				$this->getVersions(),
+				$versionsGridFieldConfig
+			);
+			$extraTasks .= '<li class="ss-ui-button" data-panel="find-versions">Versions</li>';
+			$extraFields = $versionsGrid->addExtraClass('find-versions');
+		}
+
 		$fields->add(new LiteralField('BottomTaskSelection',
 			'<div id="Actions" class="field actions"><label class="left">Actions</label><ul>'.
 			'<li class="ss-ui-button" data-panel="embargo">Embargo</li>'.
 			'<li class="ss-ui-button" data-panel="expiry">Expiry</li>'.
 			'<li class="ss-ui-button" data-panel="replace">Replace</li>'.
-			'<li class="ss-ui-button" data-panel="find-usage">Find usage</li>'.
-			'<li class="ss-ui-button" data-panel="find-references">Find references</li>'.
+			'<li class="ss-ui-button" data-panel="find-usage">Usage</li>'.
+			'<li class="ss-ui-button" data-panel="find-references">References</li>'.
+			$extraTasks.
 			'</ul></div>'));
 
 		$embargoValue = 'None';
@@ -599,7 +642,8 @@ class DMSDocument extends DataObject implements DMSDocumentInterface {
 				)->addExtraClass('expiry'),
 				$uploadField->addExtraClass('replace'),
 				$pagesGrid->addExtraClass('find-usage'),
-				$referencesGrid->addExtraClass('find-references')
+				$referencesGrid->addExtraClass('find-references'),
+				$extraFields
 		)->setName("ActionsPanel")->addExtraClass('dmsupload ss-uploadfield'));
 
 		$this->extend('updateCMSFields', $fields);
@@ -745,9 +789,18 @@ class DMSDocument_Controller extends Controller {
 	 */
 	protected function getDocumentFromID($request) {
 		$doc = null;
-		$id = Convert::raw2sql(intval($request->param('ID')));
-		$doc = DataObject::get_by_id('DMSDocument', $id);
-		$this->extend('updateDocumentFromID', $doc, $request);
+
+		$id = Convert::raw2sql($request->param('ID'));
+
+		if (strpos($id, 'version') === 0) { //versioned document
+			$id = str_replace('version','',$id);
+			$doc = DataObject::get_by_id('DMSDocument_versions', $id);
+			$this->extend('updateVersionFromID', $doc, $request);
+		} else {    //normal document
+			$doc = DataObject::get_by_id('DMSDocument', $id);
+			$this->extend('updateDocumentFromID', $doc, $request);
+		}
+
 		return $doc;
 	}
 
@@ -761,22 +814,28 @@ class DMSDocument_Controller extends Controller {
 			$canView = false;
 
 			//Runs through all pages that this page links to and sets canView to true if the user can view ONE of these pages
-			$pages = $doc->Pages();
-			if ($pages->Count() > 0) {
-				foreach($pages as $page) {
-					if ($page->CanView()) {
-						$canView = true;    //just one canView is enough to know that we can view the file
-						break;
+			if (method_exists($doc, 'Pages')) {
+				$pages = $doc->Pages();
+				if ($pages->Count() > 0) {
+					foreach($pages as $page) {
+						if ($page->CanView()) {
+							$canView = true;    //just one canView is enough to know that we can view the file
+							break;
+						}
 					}
+				} else {
+					//if the document isn't on any page, then allow viewing of the document (because there is no canView() to consult)
+					$canView = true;
 				}
-			} else {
-				//if the document isn't on any page, then allow viewing of the document (because there is no canView() to consult)
-				$canView = true;
 			}
 
 			// check for embargo or expiry
 			if ($doc->isHidden()) $canView = false;
 
+			//admins can always download any document, even if otherwise hidden
+			$member = Member::currentUser();
+			if ($member && Permission::checkMember($member, 'ADMIN')) $canView = true;
+
 			if ($canView) {
 				$path = $doc->getFullPath();
 				if ( is_file($path) ) {
diff --git a/code/DMSDocument_versions.php b/code/DMSDocument_versions.php
new file mode 100644
index 0000000..e209972
--- /dev/null
+++ b/code/DMSDocument_versions.php
@@ -0,0 +1,211 @@
+<?php
+/**
+ * DataObject to store versions of uploaded Documents. Versions are only created when replacing a document, not on every
+ * save of the DMSDocument dataobject. So, versions store the various versions of the underlying Document, not the
+ * DataObject with information about that object.
+ */
+class DMSDocument_versions extends DataObject {
+
+	static $enable_versions = true;   //flag that turns on or off versions of documents when replacing them
+
+	static $db = array(
+		'VersionCounter' => 'Int',
+		'VersionViewCount' => 'Int'
+	); //config system call in _config creates this to mirror DMSDocument
+
+	static $has_one = array(
+		'Document' => 'DMSDocument' //ID of the original DMSDocument object this is a version of
+	);
+
+	static $defaults = array(
+		'VersionCounter' => 0
+	);
+
+	static $display_fields = array(
+		'VersionCounter' => 'VersionCounter',
+		'FilenameWithoutID' => 'Filename',
+		'LastChanged' => 'LastChanged'
+	);
+
+	static $summary_fields = array(
+		'VersionCounter',
+		'FilenameWithoutID'
+	);
+
+	static $field_labels = array(
+		'FilenameWithoutID'=>'Filename'
+	);
+
+	static $default_sort = array(
+		'LastChanged' => 'DESC'
+	);
+
+
+	/**
+	 * Creates a new version of a document by moving the current file and renaming it to the versioned filename.
+	 * This method assumes that the method calling this is just about to upload a new file to replace the old file.
+	 * @static
+	 * @param DMSDocument $doc
+	 * @return bool Success or failure
+	 */
+	static function create_version(DMSDocument $doc) {
+		$success = false;
+
+		$existingPath = $doc->getFullPath();
+		if (is_file($existingPath)) {
+			$version = new DMSDocument_versions($doc);  //create a copy of the current DMSDocument as a version
+
+			$previousVersionCounter  = 0;
+			$newestExistingVersion = self::get_versions($doc)->sort(array('Created'=>'DESC','ID'=>'DESC'))->limit(1);
+			if ($newestExistingVersion && $newestExistingVersion->Count() > 0) {
+				$previousVersionCounter = $newestExistingVersion->first()->VersionCounter;
+			}
+
+			//change the filename field to a field containing the new soon-to-be versioned file
+			$version->VersionCounter = $previousVersionCounter + 1; //start versions at 1
+			$newFilename = $version->generateVersionedFilename($doc, $version->VersionCounter);
+			$version->Filename = $newFilename;
+
+			//add a relation back to the origin ID;
+			$version->DocumentID = $doc->ID;
+			$id = $version->write();
+
+			if (!empty($id)) {
+				rename($existingPath, $version->getFullPath());
+				$success = true;
+			}
+		}
+
+		return $success;
+	}
+
+	public function delete() {
+		$path = $this->getFullPath();
+		if (file_exists($path)) unlink($path);
+
+		parent::delete();
+	}
+
+	/**
+     * Returns a DataList of all previous Versions of a document (check the LastEdited date of each
+     * object to find the correct one)
+	 * @static
+	 * @param DMSDocument $doc
+	 * @return DataList List of Document objects
+	 */
+	static function get_versions(DMSDocument $doc) {
+		if (!DMSDocument_versions::$enable_versions) user_error("DMSDocument versions are disabled",E_USER_WARNING);
+		return DMSDocument_versions::get()->filter(array('DocumentID' => $doc->ID));
+	}
+
+	public function __construct($record = null, $isSingleton = false, $model = null) {
+		//check what the constructor was passed
+		$dmsObject = null;
+		if ($record && is_subclass_of($record,'DMSDocumentInterface')) {
+			$dmsObject = $record;
+			$record = null; //cancel the record creation to just create an empty object
+		}
+
+		//create the object
+		parent::__construct($record, $isSingleton, $model);
+
+		//copy the DMSDocument object, if passed into the constructor
+		if ($dmsObject) {
+			foreach(array_keys(DataObject::custom_database_fields($dmsObject->ClassName)) as $key) {
+				$this->$key = $dmsObject->$key;
+			}
+		}
+	}
+
+	/**
+	 * Returns a link to download this document from the DMS store
+	 * @return String
+	 */
+	function getLink() {
+		return Controller::join_links(Director::baseURL(),'dmsdocument/version'.$this->ID);
+	}
+
+	/**
+	 * Document versions are always hidden from outside viewing. Only admins can download them
+	 * @return bool
+	 */
+	function isHidden() {
+		return true;
+	}
+
+	/**
+	 * Returns the full filename of the document stored in this object. Can optionally specify which filename to use at the end
+	 * @return string
+	 */
+	function getFullPath($filename = null) {
+		if (!$filename) $filename = $this->Filename;
+		return DMS::get_dms_path() . DIRECTORY_SEPARATOR . $this->Folder . DIRECTORY_SEPARATOR . $filename;
+	}
+
+	function getFilenameWithoutID() {
+		$filenameParts = explode('~',$this->Filename);
+		$filename = array_pop($filenameParts);
+		return $filename;
+	}
+
+	/**
+	 * Creates a new filename for the current Document's file when replacing the current file with a new file
+	 * @param $filename The original filename to generate the versioned filename from
+	 * @return String The new filename
+	 */
+	protected function generateVersionedFilename(DMSDocument $doc, $versionCounter) {
+		$filename = $doc->Filename;
+
+		do {
+			$versionPaddingString = str_pad($versionCounter, 4, '0', STR_PAD_LEFT); //add leading zeros to make sorting accurate up to 10,000 documents
+			$newVersionFilename = preg_replace('/([0-9]+~)(.*?)/','$1~'.$versionPaddingString.'~$2',$filename);
+
+			if ($newVersionFilename == $filename || empty($newVersionFilename)) {   //sanity check for crazy document names
+				user_error('Cannot generate new document filename for file: '.$filename,E_USER_ERROR);
+			}
+
+			$versionCounter++;  //increase the counter for the next loop run, if necessary
+		} while(file_exists($this->getFullPath($newVersionFilename)));
+
+		return $newVersionFilename;
+	}
+
+	/**
+	 * Return the extension of the file associated with the document
+	 */
+	function getExtension() {
+		return strtolower(pathinfo($this->Filename, PATHINFO_EXTENSION));
+	}
+
+	function getSize() {
+		$size = $this->getAbsoluteSize();
+		return ($size) ? File::format_size($size) : false;
+	}
+
+	/**
+	 * Return the size of the file associated with the document
+	 */
+	function getAbsoluteSize() {
+		return filesize($this->getFullPath());
+	}
+
+	/**
+	 * An alias to DMSDocument::getSize()
+	 */
+	function getFileSizeFormatted(){
+		return $this->getSize();
+	}
+
+	/**
+
+	 */
+	function trackView(){
+		if ($this->ID > 0) {
+			$count = $this->VersionViewCount + 1;
+			DB::query("UPDATE \"DMSDocument_versions\" SET \"VersionViewCount\"='$count' WHERE \"ID\"={$this->ID}");
+		}
+	}
+
+}
+
+?>
\ No newline at end of file
diff --git a/tests/DMSVersioningTest.php b/tests/DMSVersioningTest.php
new file mode 100755
index 0000000..d389a0c
--- /dev/null
+++ b/tests/DMSVersioningTest.php
@@ -0,0 +1,91 @@
+<?php
+class DMSVersioningTest extends SapphireTest {
+
+	static $testFile = 'dms/tests/DMS-test-lorum-file.pdf';
+	static $testFile2 = 'dms/tests/DMS-test-document-2.pdf';
+
+	//store values to reset back to after this test runs
+	static $dmsFolderOld;
+	static $dmsFolderSizeOld;
+
+	function setUp() {
+		parent::setUp();
+
+		self::$dmsFolderOld = DMS::$dmsFolder;
+		self::$dmsFolderSizeOld = DMS::$dmsFolderSize;
+
+		//use a test DMS folder, so we don't overwrite the live one
+		DMS::$dmsFolder = 'dms-assets-test-versions';
+
+		//clear out the test folder (in case a broken test doesn't delete it)
+		$this->delete(BASE_PATH . DIRECTORY_SEPARATOR . 'dms-assets-test-versions');
+	}
+
+	function tearDown() {
+		parent::tearDown();
+
+		$d = DataObject::get("DMSDocument");
+		foreach($d as $d1) {
+			$d1->delete();
+		}
+		$t = DataObject::get("DMSTag");
+		foreach($t as $t1) {
+			$t1->delete();
+		}
+
+		//delete the test folder after the test runs
+		$this->delete(BASE_PATH . DIRECTORY_SEPARATOR . 'dms-assets-test-versions');
+
+		//set the old DMS folder back again
+		DMS::$dmsFolder = self::$dmsFolderOld;
+		DMS::$dmsFolderSize = self::$dmsFolderSizeOld;
+	}
+
+	public function delete($path) {
+		if (file_exists($path) || is_dir($path)) {
+		    $it = new RecursiveIteratorIterator(
+		        new RecursiveDirectoryIterator($path),
+		        RecursiveIteratorIterator::CHILD_FIRST
+		    );
+		    foreach ($it as $file) {
+		        if (in_array($file->getBasename(), array('.', '..'))) {
+		            continue;
+		        } elseif ($file->isDir()) {
+		            rmdir($file->getPathname());
+		        } elseif ($file->isFile() || $file->isLink()) {
+		            unlink($file->getPathname());
+		        }
+		    }
+		    rmdir($path);
+		}
+	}
+
+
+	function testDMSVersionStorage() {
+		$dms = DMS::inst();
+
+		$document = $dms->storeDocument(self::$testFile);
+
+		$this->assertNotNull($document, "Document object created");
+		$this->assertTrue(file_exists(DMS::get_dms_path() . DIRECTORY_SEPARATOR . $document->Folder . DIRECTORY_SEPARATOR . $document->Filename),"Document file copied into DMS folder");
+
+		$document->replaceDocument(self::$testFile2);
+		$document->replaceDocument(self::$testFile);
+		$document->replaceDocument(self::$testFile2);
+		$document->replaceDocument(self::$testFile);
+
+		$versionsList = $document->getVersions();
+
+		$this->assertEquals(4, $versionsList->Count(),"4 Versions created");
+		$versionsArray = $versionsList->toArray();
+
+		$this->assertEquals($versionsArray[0]->VersionCounter, 1,"Correct version count");
+		$this->assertEquals($versionsArray[1]->VersionCounter, 2,"Correct version count");
+		$this->assertEquals($versionsArray[2]->VersionCounter, 3,"Correct version count");
+		$this->assertEquals($versionsArray[3]->VersionCounter, 4,"Correct version count");
+
+	}
+
+
+
+}
\ No newline at end of file