diff --git a/core/lib/Drupal/Core/Config/ConfigFactory.php b/core/lib/Drupal/Core/Config/ConfigFactory.php
index 5d3756e..f4e44d1 100644
--- a/core/lib/Drupal/Core/Config/ConfigFactory.php
+++ b/core/lib/Drupal/Core/Config/ConfigFactory.php
@@ -312,4 +312,11 @@ public function addOverride(ConfigFactoryOverrideInterface $config_factory_overr
     $this->configFactoryOverrides[] = $config_factory_override;
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function getOverrides() {
+    return $this->configFactoryOverrides;
+  }
+
 }
diff --git a/core/lib/Drupal/Core/Config/ConfigFactoryInterface.php b/core/lib/Drupal/Core/Config/ConfigFactoryInterface.php
index 55eb6f6..cafd3fd 100644
--- a/core/lib/Drupal/Core/Config/ConfigFactoryInterface.php
+++ b/core/lib/Drupal/Core/Config/ConfigFactoryInterface.php
@@ -134,4 +134,11 @@ public function listAll($prefix = '');
    */
   public function addOverride(ConfigFactoryOverrideInterface $config_factory_override);
 
+  /**
+   * Get all added configuration factory override instances.
+   *
+   * @return ConfigFactoryOverrideInterface[]
+   *   The configuration factory override instances.
+   */
+  public function getOverrides();
 }
diff --git a/core/lib/Drupal/Core/Config/ConfigFactoryOverrideInterface.php b/core/lib/Drupal/Core/Config/ConfigFactoryOverrideInterface.php
index 06e1f3f..96c8d48 100644
--- a/core/lib/Drupal/Core/Config/ConfigFactoryOverrideInterface.php
+++ b/core/lib/Drupal/Core/Config/ConfigFactoryOverrideInterface.php
@@ -32,4 +32,24 @@ public function loadOverrides($names);
    */
   public function getCacheSuffix();
 
+  /**
+   * Reacts to default configuration installation during extension install.
+   *
+   * @param string $type
+   *   The type of extension being installed. Either 'module' or 'theme'.
+   * @param string $name
+   *   The name of the extension.
+   */
+  public function install($type, $name);
+
+  /**
+   * Reacts to configuration removal during extension uninstallation.
+   *
+   * @param string $type
+   *   The type of extension being uninstalled. Either 'module' or 'theme'.
+   * @param string $name
+   *   The name of the extension.
+   */
+  public function uninstall($type, $name);
+
 }
diff --git a/core/lib/Drupal/Core/Config/ConfigFactoryOverrideSyncInterface.php b/core/lib/Drupal/Core/Config/ConfigFactoryOverrideSyncInterface.php
new file mode 100644
index 0000000..340564c
--- /dev/null
+++ b/core/lib/Drupal/Core/Config/ConfigFactoryOverrideSyncInterface.php
@@ -0,0 +1,31 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Config\ConfigFactoryOverrideSyncInterface.
+ */
+
+namespace Drupal\Core\Config;
+
+/**
+ * Defines the interface for a configuration factory override objects that
+ * interface with export and synchronisation of config.
+ */
+interface ConfigFactoryOverrideSyncInterface {
+
+  /**
+   * @return \Drupal\Core\Config\StorageInterface[]
+   */
+  public function getStorages();
+
+  /**
+   * Processes staged override data as part of a configuration sync.
+   *
+   * @param array $context
+   *   The batch context.
+   * @param \Drupal\Core\Config\ConfigImporter $config_importer
+   *   The config importer.
+   */
+  public static function configSyncStep(&$context, ConfigImporter $config_importer);
+
+}
diff --git a/core/lib/Drupal/Core/Config/ConfigImporter.php b/core/lib/Drupal/Core/Config/ConfigImporter.php
index 6b36913..2a6741a 100644
--- a/core/lib/Drupal/Core/Config/ConfigImporter.php
+++ b/core/lib/Drupal/Core/Config/ConfigImporter.php
@@ -542,6 +542,8 @@ public function initialize() {
       $sync_steps[] = 'processExtensions';
     }
     $sync_steps[] = 'processConfigurations';
+    // Allow any overrides to hook into the import. Since overr
+    $sync_steps[] = 'processOverrides';
 
     // Allow modules to add new steps to configuration synchronization.
     $this->moduleHandler->alter('config_import_steps', $sync_steps, $this);
@@ -602,6 +604,38 @@ public function processConfigurations(array &$context) {
     }
   }
 
+  public function processOverrides(array &$context) {
+     if (!isset($context['sandbox']['overrides'])) {
+      // Allow overriders to process staged configuration.
+      $context['sandbox']['overrides'] = array();
+      $context['sandbox']['override_count'] = 0;
+      $context['sandbox']['override_progress_count'] = 0;
+      foreach ($this->configManager->getConfigFactory()->getOverrides() as $overrider) {
+        if ($overrider instanceof ConfigFactoryOverrideSyncInterface) {
+          $context['sandbox']['overrides'][] = array(get_class($overrider), 'configSyncStep');
+          $context['sandbox']['override_count']++;
+        }
+      }
+    }
+    if (empty($context['sandbox']['overrides'])) {
+      $context['finished'] = 1;
+    }
+    else {
+      $callable = current($context['sandbox']['overrides']);
+      call_user_func_array($callable, array(&$context, $this));
+      // Have to change $context['finished'] to account for the fact there maybe
+      // more that one overrider.
+      $new_finished = ($context['sandbox']['override_progress_count'] + $context['finished']) / $context['sandbox']['override_count'];
+      if ($context['finished'] == 1) {
+        // We've complete the current process - remove it.
+        array_shift($context['sandbox']['overrides']);
+
+        $context['sandbox']['override_progress_count']++;
+      }
+      $context['finished'] = $new_finished;
+    }
+  }
+
   /**
    * Finishes the batch.
    *
@@ -997,7 +1031,7 @@ public function getId() {
    */
   protected function reInjectMe() {
     $this->eventDispatcher = \Drupal::service('event_dispatcher');
-    $this->configFactory = \Drupal::configFactory();
+    $this->configManager = \Drupal::service('config.manager');
     $this->entityManager = \Drupal::entityManager();
     $this->lock = \Drupal::lock();
     $this->typedConfigManager = \Drupal::service('config.typed');
diff --git a/core/lib/Drupal/Core/Config/ConfigInstaller.php b/core/lib/Drupal/Core/Config/ConfigInstaller.php
index a22907b..b9e72e0 100644
--- a/core/lib/Drupal/Core/Config/ConfigInstaller.php
+++ b/core/lib/Drupal/Core/Config/ConfigInstaller.php
@@ -138,12 +138,12 @@ public function installDefaultConfig($type, $name) {
       // Remove configuration that already exists in the active storage.
       $sorted_config = array_diff($sorted_config, $this->activeStorage->listAll());
 
-      foreach ($sorted_config as $name) {
-        $new_config = new Config($name, $this->activeStorage, $this->eventDispatcher, $this->typedConfig);
-        if ($data[$name] !== FALSE) {
-          $new_config->setData($data[$name]);
+      foreach ($sorted_config as $config_name) {
+        $new_config = new Config($config_name, $this->activeStorage, $this->eventDispatcher, $this->typedConfig);
+        if ($data[$config_name] !== FALSE) {
+          $new_config->setData($data[$config_name]);
         }
-        if ($entity_type = $this->configManager->getEntityTypeIdByName($name)) {
+        if ($entity_type = $this->configManager->getEntityTypeIdByName($config_name)) {
 
           // If we are syncing do not create configuration entities. Pluggable
           // configuration entities can have dependencies on modules that are
@@ -159,8 +159,8 @@ public function installDefaultConfig($type, $name) {
             ->getStorage($entity_type);
           // It is possible that secondary writes can occur during configuration
           // creation. Updates of such configuration are allowed.
-          if ($this->activeStorage->exists($name)) {
-            $id = $entity_storage->getIDFromConfigName($name, $entity_storage->getEntityType()->getConfigPrefix());
+          if ($this->activeStorage->exists($config_name)) {
+            $id = $entity_storage->getIDFromConfigName($config_name, $entity_storage->getEntityType()->getConfigPrefix());
             $entity = $entity_storage->load($id);
             foreach ($new_config->get() as $property => $value) {
               $entity->set($property, $value);
@@ -179,6 +179,12 @@ public function installDefaultConfig($type, $name) {
       }
       $this->configFactory->setOverrideState($old_state);
     }
+
+    // Allow configuration factory overrides to respond to installation.
+    foreach ($this->configFactory->getOverrides() as $config_override) {
+      $config_override->install($type, $name);
+    }
+
     // Reset all the static caches and list caches.
     $this->configFactory->reset();
   }
diff --git a/core/lib/Drupal/Core/Config/ConfigManager.php b/core/lib/Drupal/Core/Config/ConfigManager.php
index 6faa23e..0fe9a72 100644
--- a/core/lib/Drupal/Core/Config/ConfigManager.php
+++ b/core/lib/Drupal/Core/Config/ConfigManager.php
@@ -156,6 +156,11 @@ public function uninstall($type, $name) {
     foreach ($config_names as $config_name) {
       $this->configFactory->get($config_name)->delete();
     }
+    // Allow configuration factory overrides to respond to uninstallation.
+    foreach ($this->configFactory->getOverrides() as $config_override) {
+      $config_override->uninstall($type, $name);
+    }
+
     $schema_dir = drupal_get_path($type, $name) . '/' . InstallStorage::CONFIG_SCHEMA_DIRECTORY;
     if (is_dir($schema_dir)) {
       // Refresh the schema cache if uninstalling an extension that provides
diff --git a/core/lib/Drupal/Core/Config/DatabaseStorage.php b/core/lib/Drupal/Core/Config/DatabaseStorage.php
index 11ab691..6509e00 100644
--- a/core/lib/Drupal/Core/Config/DatabaseStorage.php
+++ b/core/lib/Drupal/Core/Config/DatabaseStorage.php
@@ -73,18 +73,13 @@ public function exists($name) {
    * {@inheritdoc}
    */
   public function read($name) {
-    $data = FALSE;
-    try {
-      $raw = $this->connection->query('SELECT data FROM {' . $this->connection->escapeTable($this->table) . '} WHERE name = :name', array(':name' => $name), $this->options)->fetchField();
-      if ($raw !== FALSE) {
-        $data = $this->decode($raw);
-      }
+    $data = $this->readMultiple(array($name));
+    if (isset($data[$name])) {
+      return $data[$name];
     }
-    catch (\Exception $e) {
-      // If we attempt a read without actually having the database or the table
-      // available, just return FALSE so the caller can handle it.
-    }
-    return $data;
+    // @todo https://drupal.org/node/2260961 change return NULL when no
+    //   configuration object found to be consistent with other parts of Drupal.
+    return FALSE;
   }
 
   /**
diff --git a/core/modules/config/lib/Drupal/config/Controller/ConfigController.php b/core/modules/config/lib/Drupal/config/Controller/ConfigController.php
index 88cdeab..90a3dc9 100644
--- a/core/modules/config/lib/Drupal/config/Controller/ConfigController.php
+++ b/core/modules/config/lib/Drupal/config/Controller/ConfigController.php
@@ -9,6 +9,7 @@
 
 use Drupal\Core\Archiver\ArchiveTar;
 use Drupal\Component\Serialization\Yaml;
+use Drupal\Core\Config\ConfigFactoryOverrideSyncInterface;
 use Drupal\Core\Config\ConfigManagerInterface;
 use Drupal\Core\Config\StorageInterface;
 use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
@@ -89,6 +90,19 @@ public function downloadExport() {
       $archiver->addString("$name.yml", Yaml::encode(\Drupal::config($name)->get()));
     }
 
+    // Allow overriders to add files to the export.
+    foreach (\Drupal::configFactory()->getOverrides() as $overrider) {
+      if ($overrider instanceof ConfigFactoryOverrideSyncInterface) {
+        foreach ($overrider->getStorages() as $storage) {
+          // @todo consider adding getExportDir to interface. But where?
+          $overrider_dir = $storage->getExportDir();
+          foreach ($storage->listAll() as $name) {
+            $archiver->addString($overrider_dir . '/' . $name . '.yml', Yaml::encode($storage->read($name)));
+          }
+        }
+      }
+    }
+
     $request = new Request(array('file' => 'config.tar.gz'));
     return $this->fileDownloadController->download($request, 'temporary');
   }
diff --git a/core/modules/config/lib/Drupal/config/Form/ConfigSync.php b/core/modules/config/lib/Drupal/config/Form/ConfigSync.php
index a9eaac7..b13d9d4 100644
--- a/core/modules/config/lib/Drupal/config/Form/ConfigSync.php
+++ b/core/modules/config/lib/Drupal/config/Form/ConfigSync.php
@@ -8,6 +8,7 @@
 namespace Drupal\config\Form;
 
 use Drupal\Component\Uuid\UuidInterface;
+use Drupal\Core\Config\ConfigFactoryOverrideSyncInterface;
 use Drupal\Core\Config\ConfigImporterException;
 use Drupal\Core\Config\ConfigImporter;
 use Drupal\Core\Entity\EntityManagerInterface;
diff --git a/core/modules/config/lib/Drupal/config/Tests/DefaultConfigTest.php b/core/modules/config/lib/Drupal/config/Tests/DefaultConfigTest.php
index 8a5d022..d5e6fdf 100644
--- a/core/modules/config/lib/Drupal/config/Tests/DefaultConfigTest.php
+++ b/core/modules/config/lib/Drupal/config/Tests/DefaultConfigTest.php
@@ -51,9 +51,9 @@ public function testDefaultConfig() {
     $default_config_storage = new TestInstallStorage();
 
     foreach ($default_config_storage->listAll() as $config_name) {
-      // @todo: remove once migration (https://drupal.org/node/2183957) and
-      // translation (https://drupal.org/node/2168609) schemas are in.
-      if (strpos($config_name, 'migrate.migration') === 0 || strpos($config_name, 'language.config') === 0) {
+      // @todo: remove once migration (https://drupal.org/node/2183957) schemas
+      // are in.
+      if (strpos($config_name, 'migrate.migration') === 0) {
         continue;
       }
 
diff --git a/core/modules/config/tests/config_override/lib/Drupal/config_override/ConfigOverrider.php b/core/modules/config/tests/config_override/lib/Drupal/config_override/ConfigOverrider.php
index 106df3d..355869f 100644
--- a/core/modules/config/tests/config_override/lib/Drupal/config_override/ConfigOverrider.php
+++ b/core/modules/config/tests/config_override/lib/Drupal/config_override/ConfigOverrider.php
@@ -40,5 +40,17 @@ public function getCacheSuffix() {
     return 'ConfigOverrider';
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function install($type, $name) {
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function uninstall($type, $name) {
+  }
+
 }
 
diff --git a/core/modules/config/tests/config_override/lib/Drupal/config_override/ConfigOverriderLowPriority.php b/core/modules/config/tests/config_override/lib/Drupal/config_override/ConfigOverriderLowPriority.php
index a9a435e..19ea21e 100644
--- a/core/modules/config/tests/config_override/lib/Drupal/config_override/ConfigOverriderLowPriority.php
+++ b/core/modules/config/tests/config_override/lib/Drupal/config_override/ConfigOverriderLowPriority.php
@@ -41,5 +41,17 @@ public function getCacheSuffix() {
     return 'ConfigOverriderLowPriority';
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function install($type, $name) {
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function uninstall($type, $name) {
+  }
+
 }
 
diff --git a/core/modules/config/tests/config_test/config/install/language.config.de.config_test.system.yml b/core/modules/config/tests/config_test/config/install/language/de/config_test.system.yml
similarity index 100%
rename from core/modules/config/tests/config_test/config/install/language.config.de.config_test.system.yml
rename to core/modules/config/tests/config_test/config/install/language/de/config_test.system.yml
diff --git a/core/modules/config/tests/config_test/config/install/language.config.en.config_test.system.yml b/core/modules/config/tests/config_test/config/install/language/en/config_test.system.yml
similarity index 100%
rename from core/modules/config/tests/config_test/config/install/language.config.en.config_test.system.yml
rename to core/modules/config/tests/config_test/config/install/language/en/config_test.system.yml
diff --git a/core/modules/config/tests/config_test/config/install/language.config.fr.config_test.system.yml b/core/modules/config/tests/config_test/config/install/language/fr/config_test.system.yml
similarity index 100%
rename from core/modules/config/tests/config_test/config/install/language.config.fr.config_test.system.yml
rename to core/modules/config/tests/config_test/config/install/language/fr/config_test.system.yml
diff --git a/core/modules/config_translation/lib/Drupal/config_translation/Form/ConfigTranslationFormBase.php b/core/modules/config_translation/lib/Drupal/config_translation/Form/ConfigTranslationFormBase.php
index fb3ba88..13311d9 100644
--- a/core/modules/config_translation/lib/Drupal/config_translation/Form/ConfigTranslationFormBase.php
+++ b/core/modules/config_translation/lib/Drupal/config_translation/Form/ConfigTranslationFormBase.php
@@ -15,6 +15,7 @@
 use Drupal\Core\Form\BaseFormIdInterface;
 use Drupal\Core\Form\FormBase;
 use Drupal\Core\Language\Language;
+use Drupal\language\Config\LanguageConfigOverride;
 use Drupal\language\ConfigurableLanguageManagerInterface;
 use Drupal\locale\StringStorageInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
@@ -352,7 +353,7 @@ protected function buildConfigForm(Element $schema, $config_data, $base_config_d
    *   Set the configuration in this language.
    * @param \Drupal\Core\Config\Config $base_config
    *   Base configuration values, in the source language.
-   * @param \Drupal\Core\Config\Config $config_translation
+   * @param \Drupal\language\Config\LanguageConfigOverride $config_translation
    *   Translation configuration override data.
    * @param array $config_values
    *   A simple one dimensional or recursive array:
@@ -372,7 +373,7 @@ protected function buildConfigForm(Element $schema, $config_data, $base_config_d
    * @return array
    *   Translation configuration override data.
    */
-  protected function setConfig(Language $language, Config $base_config, Config $config_translation, array $config_values, $shipped_config = FALSE) {
+  protected function setConfig(Language $language, Config $base_config, LanguageConfigOverride $config_translation, array $config_values, $shipped_config = FALSE) {
     foreach ($config_values as $key => $value) {
       if (is_array($value) && !isset($value['translation'])) {
         // Traverse into this level in the configuration.
diff --git a/core/modules/language/language.install b/core/modules/language/language.install
new file mode 100644
index 0000000..7f529d5
--- /dev/null
+++ b/core/modules/language/language.install
@@ -0,0 +1,34 @@
+<?php
+
+/**
+ * @file
+ * Install, update and uninstall functions for the language module.
+ */
+
+use Drupal\language\Config\LanguageOverrideDatabaseStorage;
+
+/**
+ * Implements hook_install().
+ */
+function language_install() {
+  // Make sure that the config storage table is created.
+  $storage = \Drupal::service('language.config_storage');
+  if ($storage instanceof LanguageOverrideDatabaseStorage) {
+    $storage->ensureTableExists();
+  }
+
+  // Get all the existing modules that are enabled and install any language
+  // configuration.
+  $language_config_override = \Drupal::service('language.config_factory_override');
+  foreach (array_keys(\Drupal::moduleHandler()->getModuleList()) as $module) {
+    $language_config_override->install('module', $module);
+  }
+  /** @var \Drupal\Core\Extension\ThemeHandler $theme_handler */
+  $theme_handler = \Drupal::service('theme_handler');
+  foreach ($theme_handler->listInfo() as $theme) {
+    if ($theme->status) {
+      $language_config_override->install('theme', $theme->name);
+    }
+  }
+  \Drupal::configFactory()->reset();
+}
diff --git a/core/modules/language/language.services.yml b/core/modules/language/language.services.yml
index 7396d57..6aa5b2f 100644
--- a/core/modules/language/language.services.yml
+++ b/core/modules/language/language.services.yml
@@ -11,8 +11,18 @@ services:
     class: Drupal\language\EventSubscriber\ConfigSubscriber
     tags:
       - { name: event_subscriber }
+  language.cache_config:
+    class: Drupal\Core\Cache\CacheBackendInterface
+    tags:
+      - { name: cache.bin }
+    factory_method: get
+    factory_service: cache_factory
+    arguments: [language_config]
+  language.config_storage:
+      class: Drupal\language\Config\LanguageOverrideDatabaseStorage
+      arguments: ['@database', 'config_language']
   language.config_factory_override:
     class: Drupal\language\Config\LanguageConfigFactoryOverride
-    arguments: ['@config.storage', '@event_dispatcher', '@config.typed']
+    arguments: ['@language.config_storage', '@event_dispatcher', '@config.typed']
     tags:
       - { name: config.factory.override, priority: -254 }
diff --git a/core/modules/language/lib/Drupal/language/Config/LanguageConfigFactoryOverride.php b/core/modules/language/lib/Drupal/language/Config/LanguageConfigFactoryOverride.php
index bfadec0..8b2c81e 100644
--- a/core/modules/language/lib/Drupal/language/Config/LanguageConfigFactoryOverride.php
+++ b/core/modules/language/lib/Drupal/language/Config/LanguageConfigFactoryOverride.php
@@ -8,6 +8,9 @@
 namespace Drupal\language\Config;
 
 use Drupal\Core\Config\Config;
+use Drupal\Core\Config\ConfigImporter;
+use Drupal\Core\Config\FileStorage;
+use Drupal\Core\Config\StorageComparer;
 use Drupal\Core\Config\StorageInterface;
 use Drupal\Core\Config\TypedConfigManagerInterface;
 use Drupal\Core\Language\Language;
@@ -22,9 +25,19 @@ class LanguageConfigFactoryOverride implements LanguageConfigFactoryOverrideInte
   /**
    * The configuration storage.
    *
-   * @var \Drupal\Core\Config\StorageInterface
+   * Do not access this directly. Should be accessed through self::getStorage()
+   * so that the cache of storages per langcode is used.
+   *
+   * @var \Drupal\language\Config\LanguageOverrideStorageInterface
+   */
+  protected $baseStorage;
+
+  /**
+   * An array of configuration storages keyed by langcode.
+   *
+   * @var \Drupal\language\Config\LanguageOverrideStorageInterface[]
    */
-  protected $storage;
+  protected $storages;
 
   /**
    * The typed config manager.
@@ -50,15 +63,15 @@ class LanguageConfigFactoryOverride implements LanguageConfigFactoryOverrideInte
   /**
    * Constructs the LanguageConfigFactoryOverride object.
    *
-   * @param \Drupal\Core\Config\StorageInterface $storage
+   * @param \Drupal\language\Config\LanguageOverrideStorageInterface $storage
    *   The configuration storage engine.
    * @param \Symfony\Component\EventDispatcher\EventDispatcherInterface $event_dispatcher
    *   An event dispatcher instance to use for configuration events.
    * @param \Drupal\Core\Config\TypedConfigManagerInterface $typed_config
    *   The typed configuration manager.
    */
-  public function __construct(StorageInterface $storage, EventDispatcherInterface $event_dispatcher, TypedConfigManagerInterface $typed_config) {
-    $this->storage = $storage;
+  public function __construct(LanguageOverrideStorageInterface $storage, EventDispatcherInterface $event_dispatcher, TypedConfigManagerInterface $typed_config) {
+    $this->baseStorage = $storage;
     $this->eventDispatcher = $event_dispatcher;
     $this->typedConfigManager = $typed_config;
   }
@@ -67,72 +80,40 @@ public function __construct(StorageInterface $storage, EventDispatcherInterface
    * {@inheritdoc}
    */
   public function loadOverrides($names) {
-    $data = array();
-    $language_names = $this->getLanguageConfigNames($names);
-    if ($language_names) {
-      $data = $this->storage->readMultiple(array_values($language_names));
-      // Re-key the data array to use configuration names rather than override
-      // names.
-      $prefix_length = strlen(static::LANGUAGE_CONFIG_PREFIX . '.' . $this->language->id) + 1;
-      foreach ($data as $key => $value) {
-        unset($data[$key]);
-        $key = substr($key, $prefix_length);
-        $data[$key] = $value;
-      }
+    if ($this->language) {
+      $storage = $this->getStorage($this->language->getId());
+      return $storage->readMultiple($names);
     }
-    return $data;
+    return array();
   }
 
   /**
    * {@inheritdoc}
    */
   public function getOverride($langcode, $name) {
-    $override_name = $this->getLanguageConfigName($langcode, $name);
-    $overrides = $this->storage->read($override_name);
-    $config = new Config($override_name, $this->storage, $this->eventDispatcher, $this->typedConfigManager);
-    if (!empty($overrides)) {
-      $config->initWithData($overrides);
-    }
-    return $config;
-  }
-
-  /**
-   * Generate a list of configuration names based on base names.
-   *
-   * @param array $names
-   *   List of configuration names.
-   *
-   * @return array
-   *   List of configuration names for language override files if applicable.
-   */
-  protected function getLanguageConfigNames(array $names) {
-    $language_names = array();
-    if (isset($this->language)) {
-      foreach ($names as $name) {
-        if ($language_name = $this->getLanguageConfigName($this->language->id, $name)) {
-          $language_names[$name] = $language_name;
-        }
-      }
+    $storage = $this->getStorage($langcode);
+    $data = $storage->read($name);
+    $override = new LanguageConfigOverride($name, $storage, $this->typedConfigManager);
+    if (!empty($data)) {
+      $override->initWithData($data);
     }
-    return $language_names;
+    return $override;
   }
 
   /**
-   * Get language override name for given language and configuration name.
-   *
-   * @param string $langcode
-   *   Language code.
-   * @param string $name
-   *   Configuration name.
-   *
-   * @return bool|string
-   *   Configuration name or FALSE if not applicable.
+   * {@inheritdoc}
    */
-  protected function getLanguageConfigName($langcode, $name) {
-     if (strpos($name, static::LANGUAGE_CONFIG_PREFIX) === 0) {
-      return FALSE;
+  public function getStorage($langcode = NULL) {
+    if (!isset($langcode)) {
+      $langcode = $this->language ? $this->language->id : NULL;
     }
-    return static::LANGUAGE_CONFIG_PREFIX . '.' . $langcode . '.' . $name;
+    if (!isset($this->storages[$langcode])) {
+      // Clone the language override storage so a process could compare language
+      // overrides if it wanted to.
+      $storage = clone $this->baseStorage;
+      $this->storages[$langcode] = $storage->setLangcode($langcode);
+    }
+    return $this->storages[$langcode];
   }
 
   /**
@@ -165,4 +146,141 @@ public function setLanguageFromDefault(LanguageDefault $language_default = NULL)
     return $this;
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function install($type, $name) {
+    // Work out if this extension provides default language overrides.
+    $config_dir = drupal_get_path($type, $name) . '/config/install/language';
+    if (is_dir($config_dir)) {
+      // List all the directories.
+      // \DirectoryIterator on Windows requires an absolute path.
+      $it  = new \DirectoryIterator(realpath($config_dir));
+      foreach ($it as $dir) {
+        if (!$dir->isDot() && $dir->isDir() ) {
+          $default_language_config = new FileStorage($dir->getPathname());
+          $storage = $this->getStorage($dir->getFilename());
+          foreach ($default_language_config->listAll() as $config_name) {
+            $data = $default_language_config->read($config_name);
+            $config = new LanguageConfigOverride($config_name, $storage, $this->typedConfigManager);
+            $config->setData($data)->save();
+          }
+        }
+      }
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function uninstall($type, $name) {
+    $this->baseStorage->deleteAllOverrides($name . '.');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getStorages() {
+    $storages = array();
+    foreach (\Drupal::languageManager()->getLanguages() as $language) {
+      $storages[] = $this->getStorage($language->getId());
+    }
+    return $storages;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function configSyncStep(&$context, ConfigImporter $config_importer) {
+    // First time get create list of stuff to import.
+    if (!isset($context['sandbox']['language'])) {
+      static::initializeSandbox($context, $config_importer);
+    }
+
+    if ($to_process = static::getNextOperation($context)) {
+      list($config_name, $langcode, $op, $comparer) = $to_process;
+
+      if ($op == 'delete') {
+        $comparer->getTargetStorage()->delete($config_name);
+      }
+      else {
+        $comparer->getTargetStorage()->write($config_name, $comparer->getSourceStorage()->read($config_name));
+      }
+      $context['sandbox']['language']['data'][$langcode]['processed'][$op][] = $config_name;
+      $context['sandbox']['language']['processed']++;
+      $context['finished'] = $context['sandbox']['language']['processed'] / $context['sandbox']['language']['total_to_process'];
+      $context['message'] = \Drupal::translation()->translate('Processing @name language configuration override for langcode @langcode.', array('@name' => $config_name, '@langcode' => $langcode));
+    }
+    else {
+      $context['finished'] = 1;
+    }
+
+  }
+
+  /**
+   * Initializes the batch context with what to do.
+   *
+   * @param array $context
+   *   The batch context.
+   * @param \Drupal\Core\Config\ConfigImporter $config_importer
+   *   The config importer.
+   */
+  protected static function initializeSandbox(&$context, $config_importer) {
+    $context['sandbox']['language']['total_to_process'] = 0;
+    $context['sandbox']['language']['processed'] = 0;
+    $context['sandbox']['language']['current_langcode'] = NULL;
+    $context['sandbox']['language']['data'] = array();
+    // All languages are synced by now.
+    foreach (\Drupal::languageManager()->getLanguages() as $language) {
+      // Get the active store for the language
+      $active = \Drupal::languageManager()->getLanguageConfigOverrideStorage($language->getId());
+      // So we are tying ourselves into files unlike the current ConfigSync
+      // which is just using config.storage.staging. If we don't want to do this
+      // we are going to have to expand the staging storage functionality to
+      // deal with overrides. Which might be a good idea anyway.
+      $stage = new FileStorage(config_get_config_directory(CONFIG_STAGING_DIRECTORY) . '/language/' . $language->getId());
+      $comparer = new StorageComparer($stage, $active);
+      $comparer->createChangelist();
+      $count = 0;
+      foreach (array('delete', 'create', 'rename', 'update') as $op) {
+        $count += count($comparer->getChangelist($op));
+      }
+      if ($count > 0) {
+        $context['sandbox']['language']['data'][$language->getId()]['comparer'] = $comparer;
+        $context['sandbox']['language']['data'][$language->getId()]['processed'] = $comparer->getEmptyChangelist();
+        $context['sandbox']['language']['data'][$language->getId()]['finished'] = FALSE;
+        $context['sandbox']['language']['total_to_process'] += $count;
+      }
+    }
+  }
+
+  /**
+   * Gets the language code to process.
+   *
+   * @param $context
+   *   The batch context.
+   *
+   * @return array
+   *   An array containing data need to process the next config override.
+   */
+  protected static function getNextOperation(&$context) {
+    foreach ($context['sandbox']['language']['data'] as $langcode => $data) {
+      if (!$data['finished']) {
+        $comparer = $context['sandbox']['language']['data'][$langcode]['comparer'];
+        foreach (array('delete', 'create', 'update') as $op) {
+          $todo = array_diff($comparer->getChangelist($op), $context['sandbox']['language']['data'][$langcode]['processed'][$op]);
+          if (!empty($todo)) {
+            $return[] = array_shift($todo);
+            $return[] = $langcode;
+            $return[] = $op;
+            $return[] = $comparer;
+            return $return;
+          }
+        }
+        $context['sandbox']['language']['data'][$langcode]['finished'] = TRUE;
+      }
+    }
+    return FALSE;
+  }
+
 }
diff --git a/core/modules/language/lib/Drupal/language/Config/LanguageConfigFactoryOverrideInterface.php b/core/modules/language/lib/Drupal/language/Config/LanguageConfigFactoryOverrideInterface.php
index 1c3de55..86510d4 100644
--- a/core/modules/language/lib/Drupal/language/Config/LanguageConfigFactoryOverrideInterface.php
+++ b/core/modules/language/lib/Drupal/language/Config/LanguageConfigFactoryOverrideInterface.php
@@ -8,13 +8,14 @@
 namespace Drupal\language\Config;
 
 use Drupal\Core\Config\ConfigFactoryOverrideInterface;
+use Drupal\Core\Config\ConfigFactoryOverrideSyncInterface;
 use Drupal\Core\Language\Language;
 use Drupal\Core\Language\LanguageDefault;
 
 /**
  * Defines the interface for a configuration factory language override object.
  */
-interface LanguageConfigFactoryOverrideInterface extends ConfigFactoryOverrideInterface {
+interface LanguageConfigFactoryOverrideInterface extends ConfigFactoryOverrideInterface, ConfigFactoryOverrideSyncInterface {
 
   /**
    * Prefix for all language configuration files.
@@ -62,4 +63,15 @@ public function setLanguageFromDefault(LanguageDefault $language_default = NULL)
    */
   public function getOverride($langcode, $name);
 
+  /**
+   * Returns the storage instance for a particular langcode.
+   *
+   * @param string $langcode
+   *   Language code.
+   *
+   * @return \Drupal\language\Config\LanguageOverrideStorageInterface
+   *   The language override storage object.
+   */
+  public function getStorage($langcode);
+
 }
diff --git a/core/modules/language/lib/Drupal/language/Config/LanguageConfigOverride.php b/core/modules/language/lib/Drupal/language/Config/LanguageConfigOverride.php
new file mode 100644
index 0000000..6ed2b11
--- /dev/null
+++ b/core/modules/language/lib/Drupal/language/Config/LanguageConfigOverride.php
@@ -0,0 +1,71 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\language\Config\LanguageConfigOverride.
+ */
+
+namespace Drupal\language\Config;
+
+use Drupal\Core\Config\StorableConfigBase;
+use Drupal\Core\Config\StorageInterface;
+use Drupal\Core\Config\TypedConfigManagerInterface;
+
+/**
+ * Defines language configuration overrides.
+ */
+class LanguageConfigOverride extends StorableConfigBase {
+
+  /**
+   * Constructs a language override object.
+   *
+   * @param string $name
+   *   The name of the configuration object being overridden.
+   * @param \Drupal\Core\Config\StorageInterface $storage
+   *   A storage controller object to use for reading and writing the
+   *   configuration override.
+   * @param \Drupal\Core\Config\TypedConfigManagerInterface $typed_config
+   *   The typed configuration manager service.
+   */
+  public function __construct($name, StorageInterface $storage, TypedConfigManagerInterface $typed_config) {
+    $this->name = $name;
+    $this->storage = $storage;
+    $this->typedConfigManager = $typed_config;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function save() {
+    // Validate the configuration object name before saving.
+    static::validateName($this->name);
+
+    // If there is a schema for this configuration object, cast all values to
+    // conform to the schema.
+    if ($this->typedConfigManager->hasConfigSchema($this->name)) {
+      // Ensure that the schema wrapper has the latest data.
+      $this->schemaWrapper = NULL;
+      foreach ($this->data as $key => $value) {
+        $this->data[$key] = $this->castValue($key, $value);
+      }
+    }
+
+    $this->storage->write($this->name, $this->data);
+    $this->isNew = FALSE;
+    $this->originalData = $this->data;
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function delete() {
+    // @todo Consider to remove the pruning of data for Config::delete().
+    $this->data = array();
+    $this->storage->delete($this->name);
+    $this->isNew = TRUE;
+    $this->originalData = $this->data;
+    return $this;
+  }
+
+}
diff --git a/core/modules/language/lib/Drupal/language/Config/LanguageOverrideDatabaseStorage.php b/core/modules/language/lib/Drupal/language/Config/LanguageOverrideDatabaseStorage.php
new file mode 100644
index 0000000..f4f8853
--- /dev/null
+++ b/core/modules/language/lib/Drupal/language/Config/LanguageOverrideDatabaseStorage.php
@@ -0,0 +1,187 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\language\Config\LanguageOverrideDatabaseStorage.
+ */
+
+namespace Drupal\language\Config;
+
+use Drupal\Core\Config\DatabaseStorage;
+use Drupal\Core\Database\Database;
+use Drupal\language\Exception\LanguageOverrideStorageLockedException;
+
+/**
+ * Defines cached storage for language configuration overrides.
+ */
+class LanguageOverrideDatabaseStorage extends DatabaseStorage implements LanguageOverrideStorageInterface {
+
+  /**
+   * THe language code.
+   *
+   * @var string
+   */
+  protected $langcode;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function exists($name) {
+    try {
+      return (bool) $this->connection->queryRange('SELECT 1 FROM {' . $this->connection->escapeTable($this->table) . '} WHERE name = :name AND langcode = :langcode', 0, 1, array(
+        ':name' => $name,
+        ':langcode' => $this->langcode,
+      ), $this->options)->fetchField();
+    }
+    catch (\Exception $e) {
+      // If we attempt a read without actually having the database or the table
+      // available, just return FALSE so the caller can handle it.
+      return FALSE;
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function readMultiple(array $names) {
+    $list = array();
+    try {
+      $list = $this->connection->query('SELECT name, data FROM {' . $this->connection->escapeTable($this->table) . '} WHERE name IN (:names) AND langcode = :langcode', array(':names' => $names, ':langcode' => $this->langcode), $this->options)->fetchAllKeyed();
+      foreach ($list as &$data) {
+        $data = $this->decode($data);
+      }
+    }
+    catch (\Exception $e) {
+      // If we attempt a read without actually having the database or the table
+      // available, just return an empty array so the caller can handle it.
+    }
+    return $list;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function doWrite($name, $data) {
+    $options = array('return' => Database::RETURN_AFFECTED) + $this->options;
+    return (bool) $this->connection->merge($this->table, $options)
+      ->keys(array('name' => $name, 'langcode' => $this->langcode))
+      ->fields(array('data' => $data))
+      ->execute();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function ensureTableExists() {
+    return parent::ensureTableExists();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static function schemaDefinition() {
+    $schema = parent::schemaDefinition();
+    $schema['fields']['langcode'] = array(
+      'description' => 'The {language}.langcode of this configuration data.',
+      'type' => 'varchar',
+      'length' => 12,
+      'not null' => TRUE,
+    );
+    $schema['primary key'] = array('name', 'langcode');
+    return $schema;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function delete($name) {
+    $options = array('return' => Database::RETURN_AFFECTED) + $this->options;
+    return (bool) $this->connection->delete($this->table, $options)
+      ->condition('name', $name)
+      ->condition('langcode', $this->langcode)
+      ->execute();
+  }
+
+
+  /**
+   * {@inheritdoc}
+   */
+  public function rename($name, $new_name) {
+    $options = array('return' => Database::RETURN_AFFECTED) + $this->options;
+    return (bool) $this->connection->update($this->table, $options)
+      ->fields(array('name' => $new_name))
+      ->condition('name', $name)
+      ->execute();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function listAll($prefix = '') {
+    try {
+      return $this->connection->query('SELECT name FROM {' . $this->connection->escapeTable($this->table) . '} WHERE name LIKE :name AND langcode = :langcode', array(
+        ':name' => $this->connection->escapeLike($prefix) . '%',
+        ':langcode' => $this->langcode,
+      ), $this->options)->fetchCol();
+    }
+    catch (\Exception $e) {
+      return array();
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function deleteAll($prefix = '') {
+    try {
+      $options = array('return' => Database::RETURN_AFFECTED) + $this->options;
+      return (bool) $this->connection->delete($this->table, $options)
+        ->condition('name', $prefix . '%', 'LIKE')
+        ->condition('langcode', $this->langcode)
+        ->execute();
+    }
+    catch (\Exception $e) {
+      return FALSE;
+    }
+  }
+
+
+  /**
+   * {@inheritdoc}
+   */
+  public function deleteAllOverrides($prefix) {
+    try {
+      $options = array('return' => Database::RETURN_AFFECTED) + $this->options;
+      return (bool) $this->connection->delete($this->table, $options)
+        ->condition('name', $prefix . '%', 'LIKE')
+        ->execute();
+    }
+    catch (\Exception $e) {
+      return FALSE;
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setLangcode($langcode) {
+    // Mitigate side effects by preventing the storage's langcode changing once
+    // set. The configuration override objects returned from
+    // \Drupal\language\Config\LanguageConfigFactoryOverride::getOverride()
+    // have a storage object injected so allowing the langcode to be changed
+    // could create a mismatch between the language of the data and the storage.
+    if (isset($this->langcode) && $langcode !== $this->langcode) {
+      throw new LanguageOverrideStorageLockedException('Cannot switch language override storage langcode once it has been set.');
+    }
+    $this->langcode = $langcode;
+    return $this;
+  }
+
+  public function getExportDir() {
+    if (!isset($this->langcode)) {
+      throw new \Exception('Wha?');
+    }
+    return 'language/' . $this->langcode;
+  }
+
+}
diff --git a/core/modules/language/lib/Drupal/language/Config/LanguageOverrideStorageInterface.php b/core/modules/language/lib/Drupal/language/Config/LanguageOverrideStorageInterface.php
new file mode 100644
index 0000000..7360903
--- /dev/null
+++ b/core/modules/language/lib/Drupal/language/Config/LanguageOverrideStorageInterface.php
@@ -0,0 +1,46 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\language\Config\LanguageOverrideStorageInterface.
+ */
+
+namespace Drupal\language\Config;
+
+use Drupal\Core\Config\StorageInterface;
+
+interface LanguageOverrideStorageInterface extends StorageInterface {
+
+  /**
+   * Sets the langcode to determine the override configuration directory to use.
+   *
+   * Implementations should prevent the langcode from changing once set and
+   * throw a \Drupal\language\Exception\LanguageOverrideStorageLockedException
+   * if this occurs.
+   *
+   * @param string $langcode
+   *   The language langcode to get the directory for.
+   *
+   * @return $this
+   *   The language configuration storage.
+   *
+   * @throws \Drupal\language\Exception\LanguageOverrideStorageLockedException
+   *   Exception thrown when trying to set the langcode on a storage when
+   */
+  public function setLangcode($langcode);
+
+  /**
+   * Deletes all configuration in all languages for the given prefix.
+   *
+   * @param string $prefix
+   *   The prefix to search for.
+   *
+   * @return boolean
+   *   TRUE on success, FALSE otherwise.
+   *
+   * @see \Drupal\Core\Config\StorageInterface::deleteAll()
+   * @see \Drupal\language\Config\LanguageConfigFactoryOverride::uninstall()
+   */
+  public function deleteAllOverrides($prefix);
+
+}
diff --git a/core/modules/language/lib/Drupal/language/ConfigurableLanguageManager.php b/core/modules/language/lib/Drupal/language/ConfigurableLanguageManager.php
index 6912e26..7c77a31 100644
--- a/core/modules/language/lib/Drupal/language/ConfigurableLanguageManager.php
+++ b/core/modules/language/lib/Drupal/language/ConfigurableLanguageManager.php
@@ -410,6 +410,13 @@ public function getLanguageConfigOverride($langcode, $name) {
   /**
    * {@inheritdoc}
    */
+  public function getLanguageConfigOverrideStorage($langcode) {
+    return $this->configFactoryOverride->getStorage($langcode);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   public function getUnusedPredefinedList() {
     $languages = $this->getLanguages();
     $predefined = $this->getStandardLanguageList();
diff --git a/core/modules/language/lib/Drupal/language/ConfigurableLanguageManagerInterface.php b/core/modules/language/lib/Drupal/language/ConfigurableLanguageManagerInterface.php
index 085a170..fe6923e4 100644
--- a/core/modules/language/lib/Drupal/language/ConfigurableLanguageManagerInterface.php
+++ b/core/modules/language/lib/Drupal/language/ConfigurableLanguageManagerInterface.php
@@ -91,12 +91,24 @@ public function updateLockedLanguageWeights();
    * @param string $name
    *   The language configuration object name.
    *
-   * @return \Drupal\Core\Config\Config
+   * @return \Drupal\language\Config\LanguageConfigOverride
    *   The language config override object.
    */
   public function getLanguageConfigOverride($langcode, $name);
 
   /**
+   * Gets a language config override storage object.
+   *
+   * @param string $langcode
+   *   The language code for the override.
+   *
+   * @param \Drupal\Core\Config\StorageInterface $storage
+   *   A storage object to use for reading and writing the
+   *   configuration override.
+   */
+  public function getLanguageConfigOverrideStorage($langcode);
+
+  /**
    * Prepare a language code list for unused predefined languages.
    *
    * @return array
diff --git a/core/modules/language/lib/Drupal/language/Exception/LanguageOverrideStorageLockedException.php b/core/modules/language/lib/Drupal/language/Exception/LanguageOverrideStorageLockedException.php
new file mode 100644
index 0000000..2dec626
--- /dev/null
+++ b/core/modules/language/lib/Drupal/language/Exception/LanguageOverrideStorageLockedException.php
@@ -0,0 +1,15 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\language\Exception\LanguageOverrideStorageLockedException.
+ */
+
+namespace Drupal\language\Exception;
+
+/**
+ * Exception thrown when changing the language on a language configuration
+ * override storage object.
+ */
+class LanguageOverrideStorageLockedException extends LanguageException {
+}
diff --git a/core/modules/language/lib/Drupal/language/Tests/LanguageConfigOverrideImportTest.php b/core/modules/language/lib/Drupal/language/Tests/LanguageConfigOverrideImportTest.php
new file mode 100644
index 0000000..1ea2de1
--- /dev/null
+++ b/core/modules/language/lib/Drupal/language/Tests/LanguageConfigOverrideImportTest.php
@@ -0,0 +1,71 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\language\Tests\LanguageConfigOverrideImportTest.
+ */
+
+namespace Drupal\language\Tests;
+
+use Drupal\Core\Config\FileStorage;
+use Drupal\Core\Language\Language;
+use Drupal\simpletest\WebTestBase;
+
+class LanguageConfigOverrideImportTest extends WebTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = array('language', 'config', 'config_translation');
+
+  public static function getInfo() {
+    return array(
+      'name' => 'Language config override synchronize',
+      'description' => 'Ensures the language config overrides can be synchronized.',
+      'group' => 'Language',
+    );
+  }
+
+  public function setUp() {
+    parent::setUp();
+    $this->adminUser = $this->drupalCreateUser(array('translate configuration'));
+    $this->drupalLogin($this->adminUser);
+  }
+
+  /**
+   *
+   */
+  public function testConfigOverrideImport() {
+    language_save(new Language(array(
+      'name' => 'French',
+      'id' => 'fr',
+    )));
+    /* @var \Drupal\Core\Config\StorageInterface $staging */
+    $staging = \Drupal::service('config.storage.staging');
+    $this->copyConfig(\Drupal::service('config.storage'), $staging);
+
+    \Drupal::moduleHandler()->uninstall(array('language'));
+    // Ensure that the current site has no overrides registered to the
+    // ConfigFactory.
+    $this->rebuildContainer();
+
+    /* @var \Drupal\Core\Config\StorageInterface $override_staging */
+    $override_staging = new FileStorage(config_get_config_directory(CONFIG_STAGING_DIRECTORY) . '/language/fr');
+    // Create some overrides in staging.
+    $override_staging->write('system.site', array('name' => 'FR default site name'));
+    $override_staging->write('system.maintenance', array('message' => 'FR message: @site is currently under maintenance. We should be back shortly. Thank you for your patience'));
+
+    $this->configImporter()->import();
+    $this->rebuildContainer();
+
+    $override = \Drupal::languageManager()->getLanguageConfigOverride('fr', 'system.site');
+    $this->assertEqual('FR default site name', $override->get('name'));
+    $this->drupalGet('fr');
+    $this->assertText('FR default site name');
+
+    $this->drupalGet('admin/config/development/maintenance/translate/fr/edit');
+    $this->assertText('FR message: @site is currently under maintenance. We should be back shortly. Thank you for your patience');
+  }
+}
diff --git a/core/modules/language/tests/Drupal/language/Tests/Config/LanguageOverrideDatabaseStorageTest.php b/core/modules/language/tests/Drupal/language/Tests/Config/LanguageOverrideDatabaseStorageTest.php
new file mode 100644
index 0000000..531e721
--- /dev/null
+++ b/core/modules/language/tests/Drupal/language/Tests/Config/LanguageOverrideDatabaseStorageTest.php
@@ -0,0 +1,77 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\language\Tests\LanguageOverrideDatabaseStorageTest.
+ */
+
+namespace Drupal\language\Tests\Config;
+
+use Drupal\language\Config\LanguageOverrideDatabaseStorage;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * Tests the language override database storage.
+ *
+ * @group Drupal
+ * @group Language
+ *
+ * @coversDefaultClass \Drupal\language\Config\LanguageOverrideDatabaseStorage
+ */
+class LanguageOverrideDatabaseStorageTest extends UnitTestCase {
+
+  /**
+   * The mocked database connection.
+   *
+   * @var \Drupal\Core\Database\Connection|\PHPUnit_Framework_MockObject_MockObject
+   */
+  protected $connection;
+
+  /**
+   * (@inheritdoc}
+   */
+  public static function getInfo() {
+    return array(
+      'name' => 'Language override database storage test',
+      'description' => 'Tests the language override database storage',
+      'group' => 'Language',
+    );
+  }
+
+  /**
+   * Sets necessary mock objects for testing LanguageOverrideDatabaseStorage.
+   */
+  public function setUp() {
+    $this->connection = $this->getMockBuilder('Drupal\Core\Database\Connection')
+      ->disableOriginalConstructor()
+      ->getMock();
+  }
+
+  /**
+   * Tests that the langcode can be set on the storage.
+   *
+   * This set exists to provide ensure that the exception is not being thrown
+   * on the first call to
+   * \Drupal\language\Config\LanguageOverrideDatabaseStorage::setLangcode().
+   *
+   * @covers ::setLangcode
+   */
+  public function testSetLangcode() {
+    $storage = new LanguageOverrideDatabaseStorage($this->connection, 'language_config');
+    $storage->setLangcode('en');
+    $this->assertTrue(TRUE, 'The langcode can be set.');
+  }
+
+  /**
+   * Tests that the langcode can only be set once on the storage.
+   *
+   * @expectedException \Drupal\language\Exception\LanguageOverrideStorageLockedException
+   *
+   * @covers ::setLangcode
+   */
+  public function testSetLangcodeException() {
+    $storage = new LanguageOverrideDatabaseStorage($this->connection, 'language_config');
+    $storage->setLangcode('en');
+    $storage->setLangcode('fr');
+  }
+}
diff --git a/core/modules/locale/lib/Drupal/locale/LocaleConfigManager.php b/core/modules/locale/lib/Drupal/locale/LocaleConfigManager.php
index 3c0dc57..f731b13 100644
--- a/core/modules/locale/lib/Drupal/locale/LocaleConfigManager.php
+++ b/core/modules/locale/lib/Drupal/locale/LocaleConfigManager.php
@@ -230,9 +230,9 @@ public function getStringNames(array $lids) {
    *   Language code to delete.
    */
   public function deleteLanguageTranslations($langcode) {
-    $locale_name = LanguageConfigFactoryOverrideInterface::LANGUAGE_CONFIG_PREFIX . '.' . $langcode . '.';
-    foreach ($this->configStorage->listAll($locale_name) as $name) {
-      $this->configStorage->delete($name);
+    $storage = $this->languageManager->getLanguageConfigOverrideStorage($langcode);
+    foreach ($storage->listAll() as $name) {
+      $this->languageManager->getLanguageConfigOverride($langcode, $name)->delete();
     }
   }
 
diff --git a/core/modules/locale/tests/modules/locale_test/config/install/language.config.de.locale_test.translation.yml b/core/modules/locale/tests/modules/locale_test/config/install/language/de/locale_test.translation.yml
similarity index 100%
rename from core/modules/locale/tests/modules/locale_test/config/install/language.config.de.locale_test.translation.yml
rename to core/modules/locale/tests/modules/locale_test/config/install/language/de/locale_test.translation.yml
diff --git a/core/modules/system/tests/modules/menu_test/config/install/language.config.nl.menu_test.menu_item.yml b/core/modules/system/tests/modules/menu_test/config/install/language/nl/menu_test.menu_item.yml
similarity index 100%
rename from core/modules/system/tests/modules/menu_test/config/install/language.config.nl.menu_test.menu_item.yml
rename to core/modules/system/tests/modules/menu_test/config/install/language/nl/menu_test.menu_item.yml
diff --git a/core/modules/tour/tests/tour_test/config/install/language.config.it.tour.tour.tour-test.yml b/core/modules/tour/tests/tour_test/config/install/language/it/tour.tour.tour-test.yml
similarity index 100%
rename from core/modules/tour/tests/tour_test/config/install/language.config.it.tour.tour.tour-test.yml
rename to core/modules/tour/tests/tour_test/config/install/language/it/tour.tour.tour-test.yml