diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index e26cb36..00b2395 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -2458,9 +2458,13 @@ function drupal_container(Container $reset = NULL) {
     $container->register('config.storage', 'Drupal\Core\Config\DatabaseStorage')
       ->addArgument('%config.storage.options%');
 
+    $container->register('config.globaloverridesubscriber', 'Drupal\Core\EventSubscriber\ConfigGlobalOverrideSubscriber');
+    $container->register('dispatcher', 'Symfony\Component\EventDispatcher\EventDispatcher')
+      ->addMethodCall('addSubscriber', array(new Reference('config.globaloverridesubscriber')));
     // Register configuration object factory.
     $container->register('config.factory', 'Drupal\Core\Config\ConfigFactory')
-      ->addArgument(new Reference('config.storage'));
+      ->addArgument(new Reference('config.storage'))
+      ->addArgument(new Reference('dispatcher'));
   }
   return $container;
 }
diff --git a/core/includes/config.inc b/core/includes/config.inc
index 347bf85..78032ca 100644
--- a/core/includes/config.inc
+++ b/core/includes/config.inc
@@ -65,7 +65,7 @@ function config_get_storage_names_with_prefix($prefix = '') {
  *   A configuration object.
  */
 function config($name) {
-  return drupal_container()->get('config.factory')->get($name)->load();
+  return drupal_container()->get('config.factory')->get($name);
 }
 
 /**
@@ -194,11 +194,10 @@ function config_import_invoke_owner(array $config_changes, StorageInterface $sou
       // handle the configuration change.
       $handled_by_module = FALSE;
       if (module_hook($module, 'config_import_' . $op)) {
-        $old_config = new Config($name, $target_storage);
-        $old_config->load();
+        $old_config = new Config($name, $target_storage, drupal_container()->get('dispatcher'));
 
         $data = $source_storage->read($name);
-        $new_config = new Config($name, $target_storage);
+        $new_config = new Config($name, $target_storage, drupal_container()->get('dispatcher'));
         if ($data !== FALSE) {
           $new_config->setData($data);
         }
diff --git a/core/lib/Drupal/Core/Config/Config.php b/core/lib/Drupal/Core/Config/Config.php
index 10bf925..0f2d19d 100644
--- a/core/lib/Drupal/Core/Config/Config.php
+++ b/core/lib/Drupal/Core/Config/Config.php
@@ -8,6 +8,7 @@
 namespace Drupal\Core\Config;
 
 use Drupal\Component\Utility\NestedArray;
+use Symfony\Component\EventDispatcher\EventDispatcher;
 
 /**
  * Defines the default configuration object.
@@ -50,13 +51,20 @@ class Config {
   protected $overriddenData;
 
   /**
-   * The storage used for reading and writing.
+   * The storage used to load and save this configuration object.
    *
    * @var Drupal\Core\Config\StorageInterface
    */
   protected $storage;
 
   /**
+   * The event dispatcher used to notify subscribers.
+   *
+   * @var Symfony\Component\EventDispatcher\EventDispatcher
+   */
+  protected $eventDispatcher;
+
+  /**
    * Constructs a configuration object.
    *
    * @param string $name
@@ -64,10 +72,13 @@ class Config {
    * @param Drupal\Core\Config\StorageInterface $storage
    *   A storage controller object to use for reading and writing the
    *   configuration data.
+   * @param Symfony\Component\EventDispatcher\EventDispatcher $event_dispatcher
+   *   The event dispatcher used to notify subscribers.
    */
-  public function __construct($name, StorageInterface $storage) {
+  public function __construct($name, StorageInterface $storage, EventDispatcher $event_dispatcher) {
     $this->name = $name;
     $this->storage = $storage;
+    $this->eventDispatcher = $event_dispatcher;
   }
 
   /**
@@ -89,6 +100,7 @@ class Config {
    * Returns whether this configuration object is new.
    */
   public function isNew() {
+    $this->build();
     return $this->isNew;
   }
 
@@ -120,9 +132,7 @@ class Config {
    *   The data that was requested.
    */
   public function get($key = '') {
-    if (!isset($this->overriddenData)) {
-      $this->setOverriddenData();
-    }
+    $this->build();
     if (empty($key)) {
       return $this->overriddenData;
     }
@@ -146,8 +156,7 @@ class Config {
    */
   public function setData(array $data) {
     $this->data = $data;
-    $this->resetOverriddenData();
-    return $this;
+    return $this->rebuild();
   }
 
   /**
@@ -160,32 +169,7 @@ class Config {
    */
   public function setOverride(array $data) {
     $this->overrides = $data;
-    $this->resetOverriddenData();
-    return $this;
-  }
-
-  /**
-   * Sets the current data for this configuration object.
-   *
-   * Merges overridden configuration data into the original data.
-   */
-  protected function setOverriddenData() {
-    $this->overriddenData = $this->data;
-    if (!empty($this->overrides)) {
-      $this->overriddenData = NestedArray::mergeDeepArray(array($this->overriddenData, $this->overrides));
-    }
-    return $this;
-  }
-
-  /**
-   * Resets the current data, so overrides are re-applied.
-   *
-   * This method should be called after the original data or the overridden data
-   * has been changed.
-   */
-  protected function resetOverriddenData() {
-    unset($this->overriddenData);
-    return $this;
+    return $this->rebuild();
   }
 
   /**
@@ -197,6 +181,7 @@ class Config {
    *   @todo
    */
   public function set($key, $value) {
+    $this->build();
     // Type-cast value into a string.
     $value = $this->castValue($value);
 
@@ -209,8 +194,7 @@ class Config {
     else {
       NestedArray::setValue($this->data, $parts, $value);
     }
-    $this->resetOverriddenData();
-    return $this;
+    return $this->rebuild();
   }
 
   /**
@@ -259,6 +243,7 @@ class Config {
    *   Name of the key whose value should be unset.
    */
   public function clear($key) {
+    $this->build();
     $parts = explode('.', $key);
     if (count($parts) == 1) {
       unset($this->data[$key]);
@@ -267,7 +252,7 @@ class Config {
       NestedArray::unsetValue($this->data, $parts);
     }
     $this->resetOverriddenData();
-    return $this;
+    return $this->rebuild();
   }
 
   /**
@@ -283,17 +268,20 @@ class Config {
       $this->isNew = FALSE;
       $this->setData($data);
     }
-    return $this;
+    $this->notify('load');
+    return $this->rebuild();
   }
 
   /**
    * Saves the configuration object.
    */
   public function save() {
+    $this->build();
     $this->sortByKey($this->data);
     $this->storage->write($this->name, $this->data);
     $this->isNew = FALSE;
-    return $this;
+    $this->notify('save');
+    return $this->rebuild();
   }
 
   /**
@@ -323,7 +311,51 @@ class Config {
     $this->data = array();
     $this->storage->delete($this->name);
     $this->isNew = TRUE;
-    $this->resetOverriddenData();
+    $this->notify('delete');
+    return $this->rebuild();
+  }
+
+  /**
+   * Build the data for this configuration object.
+   *
+   * Loads the base data if not loaded, and builds the overriddenData runtime
+   * configuration computing the overridden values.
+   */
+  public function build() {
+    if (!isset($this->overriddenData)) {
+      if (!isset($this->data)) {
+        $this->load();
+      }
+      $this->overriddenData = $this->data;
+      if (!empty($this->overrides)) {
+        $this->overriddenData = NestedArray::mergeDeepArray(array($this->overriddenData, $this->overrides));
+      }
+    }
     return $this;
   }
+
+  /**
+   * Resets the current data, so overrides are re-applied.
+   *
+   * This method should be called after the original data or the overridden data
+   * has been changed.
+   */
+  public function rebuild() {
+    unset($this->overriddenData);
+    return $this->build();
+  }
+
+  /**
+   * Retrieve the storage used to load and save this configuration object.
+   */
+  public function getStorage() {
+    return $this->storage;
+  }
+
+  /**
+   * Dispatch a config event.
+   */
+  public function notify($config_event_name) {
+    $this->eventDispatcher->dispatch('config.' . $config_event_name, new ConfigEvent($this));
+  }
 }
diff --git a/core/lib/Drupal/Core/Config/ConfigFactory.php b/core/lib/Drupal/Core/Config/ConfigFactory.php
index 4bf5b62..1d1dec3 100644
--- a/core/lib/Drupal/Core/Config/ConfigFactory.php
+++ b/core/lib/Drupal/Core/Config/ConfigFactory.php
@@ -7,6 +7,8 @@
 
 namespace Drupal\Core\Config;
 
+use Symfony\Component\EventDispatcher\EventDispatcher;
+
 /**
  * Defines the configuration object factory.
  *
@@ -30,14 +32,24 @@ class ConfigFactory {
   protected $storage;
 
   /**
+   * An event dispatcher instance to use for configuration events.
+   *
+   * @var Symfony\Component\EventDispatcher\EventDispatcher
+   */
+  protected $eventDispatcher;
+
+  /**
    * Constructs the Config factory.
    *
    * @param Drupal\Core\Config\StorageInterface $storage
    *   The storage controller object to use for reading and writing
    *   configuration data.
+   * @param Symfony\Component\EventDispatcher\EventDispatcher
+   *   An event dispatcher instance to use for configuration events.
    */
-  public function __construct(StorageInterface $storage) {
+  public function __construct(StorageInterface $storage, EventDispatcher $event_dispatcher) {
     $this->storage = $storage;
+    $this->eventDispatcher = $event_dispatcher;
   }
 
   /**
@@ -70,12 +82,9 @@ class ConfigFactory {
     // @todo The decrease of CPU time is interesting, since that means that
     //   ContainerBuilder involves plenty of function calls (which are known to
     //   be slow in PHP).
-    $config = new Config($name, $this->storage);
+    $config = new Config($name, $this->storage, $this->eventDispatcher);
+    $this->eventDispatcher->dispatch('config.create', new ConfigEvent($config));
 
-    // Set overridden values from global $conf, if any.
-    if (isset($conf[$name])) {
-      $config->setOverride($conf[$name]);
-    }
     return $config;
   }
 
diff --git a/core/lib/Drupal/Core/CoreBundle.php b/core/lib/Drupal/Core/CoreBundle.php
index b0830a0..f8e8691 100644
--- a/core/lib/Drupal/Core/CoreBundle.php
+++ b/core/lib/Drupal/Core/CoreBundle.php
@@ -58,6 +58,7 @@ class CoreBundle extends Bundle
     $dispatcher->addSubscriber(new \Drupal\Core\EventSubscriber\LegacyControllerSubscriber());
     $dispatcher->addSubscriber(new \Drupal\Core\EventSubscriber\FinishResponseSubscriber());
     $dispatcher->addSubscriber(new \Drupal\Core\EventSubscriber\RequestCloseSubscriber());
+    $dispatcher->addSubscriber(new \Drupal\Core\EventSubscriber\ConfigGlobalOverrideSubscriber());
     $container->set('content_negotiation', $content_negotation);
     $dispatcher->addSubscriber(\Drupal\Core\ExceptionController::getExceptionListener($container));
     /*
@@ -85,6 +86,7 @@ class CoreBundle extends Bundle
       ->addTag('kernel.event_subscriber');
     $container->register('request_close_subscriber', 'Drupal\Core\EventSubscriber\RequestCloseSubscriber')
       ->addTag('kernel.event_subscriber');
+    $container->register('config_global_override_subscriber', '\Drupal\Core\EventSubscriber\ConfigGlobalOverrideSubscriber');
     $container->register('database', 'Drupal\Core\Database\Connection')
       ->setFactoryClass('Drupal\Core\Database\Database')
       ->setFactoryMethod('getConnection')
diff --git a/core/lib/Drupal/Core/EventSubscriber/ConfigGlobalOverrideSubscriber.php b/core/lib/Drupal/Core/EventSubscriber/ConfigGlobalOverrideSubscriber.php
new file mode 100644
index 0000000..d17fcfc
--- /dev/null
+++ b/core/lib/Drupal/Core/EventSubscriber/ConfigGlobalOverrideSubscriber.php
@@ -0,0 +1,39 @@
+<?php
+/**
+ * @file
+ * Definition of Drupal\Core\EventSubscriber\ConfigGlobalOverrideSubscriber.
+ */
+
+namespace Drupal\Core\EventSubscriber;
+
+use Drupal\Core\Config\Config;
+use Drupal\Core\Config\ConfigEvent;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
+/**
+ * Override configuration values with values in global $conf variable.
+ */
+class ConfigGlobalOverridesubscriber implements EventSubscriberInterface {
+  /**
+   * Override configuration values with global $conf
+   *
+   * @param Drupal\Core\Config\ConfigEvent $event
+   *   The Event to process.
+   */
+  public function configCreate(ConfigEvent $event) {
+    global $conf;
+
+    $config = $event->getConfig();
+    if (isset($conf[$config->getName()])) {
+      $config->setOverride($conf[$config->getName()]);
+    }
+  }
+
+  /**
+   * Implements EventSubscriberInterface::getSubscribedEvents().
+   */
+  static function getSubscribedEvents() {
+    $events['config.create'][] = array('configCreate', 30);
+    return $events;
+  }
+}
diff --git a/core/modules/locale/locale.module b/core/modules/locale/locale.module
index f7c22c1..b08c35a 100644
--- a/core/modules/locale/locale.module
+++ b/core/modules/locale/locale.module
@@ -12,6 +12,7 @@
  */
 
 use Drupal\locale\LocaleLookup;
+use Drupal\locale\LocaleConfigSubscriber;
 
 /**
  * Regular expression pattern used to localize JavaScript strings.
@@ -879,3 +880,11 @@ function _locale_rebuild_js($langcode = NULL) {
       return TRUE;
   }
 }
+
+/**
+ * Implements hook_language_init().
+ */
+function locale_language_init() {
+  // Add locale helper to configuration subscribers.
+  drupal_container()->get('dispatcher')->addSubscriber(new LocaleConfigSubscriber());
+}