diff --git a/core/includes/config.inc b/core/includes/config.inc
index f1b3ce2..d871287 100644
--- a/core/includes/config.inc
+++ b/core/includes/config.inc
@@ -2,9 +2,7 @@
 
 use Drupal\Core\Config\Config;
 use Drupal\Core\Config\FileStorage;
-use Drupal\Core\Config\Context\AdminContext;
-use Drupal\Core\Config\ContextInterface;
-use Drupal\Core\Config\NullStorage;
+use Drupal\Core\Config\Context\ContextInterface;
 use Drupal\Core\Config\StorageInterface;
 
 /**
@@ -94,26 +92,14 @@ function config_get_storage_names_with_prefix($prefix = '') {
  *   a configuration file. For @code config('book.admin') @endcode, the config
  *   object returned will contain the contents of book.admin configuration file.
  *
+ * @param \Drupal\Core\Config\Context\ContextInterface $context
+ *   (Optional) The configuration context to use.
+ *
  * @return Drupal\Core\Config\Config
  *   A configuration object.
  */
-function config($name) {
-  return drupal_container()->get('config.factory')->get($name);
-}
-
-/**
- * Sets the context on the configuration object factory.
- *
- * @param \Drupal\Core\Config\ContextInterface $context
- *   The configuration context to set on the factory.
- *
- * @return Drupal\Core\Config\ContextInterface $context
- *   The configuration context that was previously set in the config factory.
- */
-function config_factory_set_context(ContextInterface $context) {
-  $current_context = drupal_container()->get('config.factory')->getContext();
-  drupal_container()->get('config.factory')->setContext($context);
-  return $current_context;
+function config($name, ContextInterface $context = NULL) {
+  return drupal_container()->get('config.factory')->get($name, $context);
 }
 
 /**
@@ -190,11 +176,11 @@ function config_sync_get_changes(StorageInterface $source_storage, StorageInterf
  *   The storage to synchronize configuration to.
  */
 function config_sync_changes(array $config_changes, StorageInterface $source_storage, StorageInterface $target_storage) {
-  $target_context = new AdminContext('config.target', $target_storage);
+  $target_context = drupal_container()->get('config.context.admin');
   $factory = drupal_container()->get('config.factory');
   foreach (array('delete', 'create', 'change') as $op) {
     foreach ($config_changes[$op] as $name) {
-      $config = new Config($name, $target_context);
+      $config = new Config($name, $target_storage, $target_context);
       if ($op == 'delete') {
         $config->delete();
       }
@@ -261,8 +247,9 @@ function config_import() {
  * @todo Add support for other extension types; e.g., themes etc.
  */
 function config_import_invoke_owner(array $config_changes, StorageInterface $source_storage, StorageInterface $target_storage) {
-  $target_context = new AdminContext('config.target', $target_storage);
-  $source_context = new AdminContext('config.target', $source_storage);
+  // Use the admin context for config importing so that any global overrides do
+  // not pollute the import.
+  $admin_context = drupal_container()->get('config.context.admin');
   // Allow modules to take over configuration change operations for
   // higher-level configuration data.
   // First pass deleted, then new, and lastly changed configuration, in order to
@@ -276,11 +263,11 @@ function config_import_invoke_owner(array $config_changes, StorageInterface $sou
       // Validate the configuration object name before importing it.
       Config::validateName($name);
       if ($entity_type = config_get_entity_type_by_name($name)) {
-        $old_config = new Config($name, $target_context);
+        $old_config = new Config($name, $target_storage, $admin_context);
         $old_config->load();
 
         $data = $source_storage->read($name);
-        $new_config = new Config($name, $source_context);
+        $new_config = new Config($name, $source_storage, $admin_context);
         if ($data !== FALSE) {
           $new_config->setData($data);
         }
diff --git a/core/includes/install.core.inc b/core/includes/install.core.inc
index 6eb1db8..8b48174 100644
--- a/core/includes/install.core.inc
+++ b/core/includes/install.core.inc
@@ -337,10 +337,15 @@ function install_begin_request(&$install_state) {
     $container->register('event_dispatcher', 'Symfony\Component\EventDispatcher\EventDispatcher');
 
     $container->register('config.storage', 'Drupal\Core\Config\InstallStorage');
-    $container->register('config.context', 'Drupal\Core\Config\Context\ConfigContext')
-      ->addArgument(new Reference('config.storage'))
+    $container->register('config.context.factory', 'Drupal\Core\Config\Context\ConfigContextFactory')
       ->addArgument(new Reference('event_dispatcher'));
+
+    $container->register('config.context', 'Drupal\Core\Config\Context\ContextInterface')
+      ->setFactoryService(new Reference('config.context.factory'))
+      ->setFactoryMethod('get');
+
     $container->register('config.factory', 'Drupal\Core\Config\ConfigFactory')
+      ->addArgument(new Reference('config.storage'))
       ->addArgument(new Reference('config.context'));
 
     // Register the 'language_manager' service.
diff --git a/core/lib/Drupal/Core/Config/Config.php b/core/lib/Drupal/Core/Config/Config.php
index a65d302..0337d28 100644
--- a/core/lib/Drupal/Core/Config/Config.php
+++ b/core/lib/Drupal/Core/Config/Config.php
@@ -9,7 +9,7 @@
 
 use Drupal\Component\Utility\NestedArray;
 use Drupal\Core\Config\ConfigNameException;
-use Drupal\Core\Config\ContextInterface;
+use Drupal\Core\Config\Context\ContextInterface;
 
 /**
  * Defines the default configuration object.
@@ -73,7 +73,7 @@ class Config {
   /**
    * The configuration context used for this configuration object.
    *
-   * @var Drupal\Core\Config\ContextInterface
+   * @var \Drupal\Core\Config\Context\ContextInterface
    */
   protected $context;
 
@@ -89,13 +89,16 @@ class Config {
    *
    * @param string $name
    *   The name of the configuration object being constructed.
-   * @param \Drupal\Core\Config\ContextInterface $context
+   * @param \Drupal\Core\Config\StorageInterface $storage
+   *   A storage controller object to use for reading and writing the
+   *   configuration data.
+   * @param \Drupal\Core\Config\Context\ContextInterface $context
    *   The configuration context used for this configuration object.
    */
-  public function __construct($name, ContextInterface $context) {
+  public function __construct($name, StorageInterface $storage, ContextInterface $context) {
     $this->name = $name;
+    $this->storage = $storage;
     $this->context = $context;
-    $this->storage = $context->getStorage();
   }
 
   /**
@@ -475,6 +478,16 @@ public function delete() {
   }
 
   /**
+   * Retrieve the storage used to load and save this configuration object.
+   *
+   * @return \Drupal\Core\Config\StorageInterface
+   *   The configuration storage object.
+   */
+  public function getStorage() {
+    return $this->storage;
+  }
+
+  /**
    * Dispatch a config event.
    */
   protected function notify($config_event_name) {
diff --git a/core/lib/Drupal/Core/Config/ConfigEvent.php b/core/lib/Drupal/Core/Config/ConfigEvent.php
index 7a13e55..c1df902 100644
--- a/core/lib/Drupal/Core/Config/ConfigEvent.php
+++ b/core/lib/Drupal/Core/Config/ConfigEvent.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\Core\Config;
 
+use Drupal\Core\Config\Context\ContextInterface;
 use Symfony\Component\EventDispatcher\Event;
 
 class ConfigEvent extends Event {
@@ -16,14 +17,14 @@ class ConfigEvent extends Event {
   /**
    * Configuration context object.
    *
-   * @var Drupal\Core\Config\ContextInterface
+   * @var \Drupal\Core\Config\Context\ContextInterface
    */
   protected $context;
 
   /**
    * Constructs a configuration event object.
    *
-   * @param \Drupal\Core\Config\ContextInterface
+   * @param \Drupal\Core\Config\Context\ContextInterface
    *   Configuration context object.
    * @param \Drupal\Core\Config\Config
    *   (optional) Configuration object.
@@ -43,7 +44,7 @@ public function getConfig() {
   /**
    * Get configuration context object.
    *
-   * @return Drupal\Core\Config\ContextInterface
+   * @return \Drupal\Core\Config\Context\ContextInterface
    *   Configuration context.
    */
   public function getContext() {
diff --git a/core/lib/Drupal/Core/Config/ConfigFactory.php b/core/lib/Drupal/Core/Config/ConfigFactory.php
index eda9324..2ff8910 100644
--- a/core/lib/Drupal/Core/Config/ConfigFactory.php
+++ b/core/lib/Drupal/Core/Config/ConfigFactory.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\Core\Config;
 
-use Drupal\Core\Config\ContextInterface;
+use Drupal\Core\Config\Context\ContextInterface;
 
 /**
  * Defines the configuration object factory.
@@ -17,20 +17,32 @@
  *
  * @see Drupal\Core\Config\Config
  *
+ * Each configuration object gets a storage controller object injected, which
+ * is used for reading and writing the configuration data.
+ *
+ * @see Drupal\Core\Config\StorageInterface
+ *
  * A configuration context is an object containing parameters that will be
  * available to the configuration plug-ins for them to customize the
  * configuration data in different ways.
  *
- * @see Drupal\Core\Config\StorageInterface
+ * @see Drupal\Core\Config\Context\ContextInterface
  */
 class ConfigFactory {
 
   /**
+   * A storage controller instance for reading and writing configuration data.
+   *
+   * @var \Drupal\Core\Config\StorageInterface
+   */
+  protected $storage;
+
+  /**
    * The default configuration context associated with this factory.
    *
-   * @var Drupal\Core\Config\ContextInterface
+   * @var \Drupal\Core\Config\Context\ContextInterface
    */
-  protected  $context;
+  protected $context;
 
   /**
    * Cached configuration objects.
@@ -42,10 +54,13 @@ class ConfigFactory {
   /**
    * Constructs the Config factory.
    *
-   * @param \Drupal\Core\Config\ContextInterface
+   * @param \Drupal\Core\Config\StorageInterface
+   *   The configuration storage engine.
+   * @param \Drupal\Core\Config\Context\ContextInterface
    *   Configuration context object.
    */
-  public function __construct(ContextInterface $context) {
+  public function __construct(StorageInterface $storage, ContextInterface $context) {
+    $this->storage = $storage;
     $this->setContext($context);
   }
 
@@ -54,14 +69,19 @@ public function __construct(ContextInterface $context) {
    *
    * @param string $name
    *   The name of the configuration object to construct.
+   * @param \Drupal\Core\Config\Context\ContextInterface $context
+   *   (Optional) The configuration context to use.
    */
-  public function get($name) {
-    $cache_key = get_class($this->getContext()) . ':' . $name;
+  public function get($name, ContextInterface $context = NULL) {
+    if ($context) {
+      $this->setContext($context);
+    }
+    $cache_key = $this->getCacheKey($name);
     if (isset($this->cache[$cache_key])) {
       return $this->cache[$cache_key];
     }
 
-    $this->cache[$cache_key] = new Config($name, $this->getContext());
+    $this->cache[$cache_key] = new Config($name, $this->storage, $this->getContext());
     return $this->cache[$cache_key]->init();
   }
 
@@ -74,7 +94,7 @@ public function get($name) {
    */
   public function reset($name = NULL) {
     if ($name) {
-      $cache_key = get_class($this->getContext()) . ':' . $name;
+      $cache_key = $this->getCacheKey($name);
       if (isset($this->cache[$cache_key])) {
         $this->cache[$cache_key]->init();
       }
@@ -97,8 +117,8 @@ public function reset($name = NULL) {
    * @todo D8: Remove after http://drupal.org/node/1865206.
    */
   public function rename($old_name, $new_name) {
-    $old_cache_key = get_class($this->getContext()) . ':' . $old_name;
-    $new_cache_key = get_class($this->getContext()) . ':' . $new_name;
+    $old_cache_key = $this->getCacheKey($old_name);
+    $new_cache_key = $this->getCacheKey($new_name);
     if (isset($this->cache[$old_cache_key])) {
       $config = $this->cache[$old_cache_key];
       // Clone the object into the existing slot.
@@ -113,7 +133,7 @@ public function rename($old_name, $new_name) {
   /**
    * Gets the default context for this factory.
    *
-   * @return Drupal\Core\Config\ContextInterface
+   * @return Drupal\Core\Config\Context\ContextInterface
    *   A configuration context instance.
    */
   public function getContext() {
@@ -123,11 +143,21 @@ public function getContext() {
   /**
    * Sets the default context for this factory.
    *
-   * @param \Drupal\Core\Config\ContextInterface $context
+   * @param \Drupal\Core\Config\Context\ContextInterface $context
    *   Context to use to get the configuration.
    */
   public function setContext($context) {
     $this->context = $context;
   }
+
+  /*
+   * Gets the cache key for a given config name in a particular context.
+   *
+   * @return string
+   *   The cache key.
+   */
+  public function getCacheKey($name) {
+    return $this->getContext()->getUuid() . ':' . $name;
+  }
 }
 
diff --git a/core/lib/Drupal/Core/Config/Context/AdminContext.php b/core/lib/Drupal/Core/Config/Context/AdminContext.php
deleted file mode 100644
index 4424623..0000000
--- a/core/lib/Drupal/Core/Config/Context/AdminContext.php
+++ /dev/null
@@ -1,40 +0,0 @@
-<?php
-
-/**
- * @file
- * Contains Drupal\Core\Config\AdminContext.
- */
-
-namespace Drupal\Core\Config\Context;
-
-use Drupal\Core\KeyValueStore\MemoryStorage;
-use Drupal\Core\Config\StorageInterface;
-use Symfony\Component\EventDispatcher\EventDispatcher;
-
-/**
- * Defines a configuration context for administration operations.
- *
- * This context won't get overrides from global $conf and will have a unique
- * name depending on the operation to perform. It can be used for importing
- * or exporting configuration or for administrative operations.
- */
-class AdminContext extends ConfigContext {
-
-  /**
-   * Overrides \Drupal\Core\Config\ConfigContext::__construct().
-   *
-   * @param string $name
-   *   Context name that may have any string value. Some names used in Drupal
-   *   core are 'config.source', 'config.target', 'system.config'.
-   * @param \Drupal\Core\Config\StorageInterface $storage
-   *   (optional) The storage controller object to use for reading and writing
-   *   configuration data. Defaults to the storage controller object registered
-   *   in the Drupal Container.
-   */
-  public function __construct($name, StorageInterface $storage = NULL) {
-    $this->set(self::ADMIN, $name);
-    $this->set($name, TRUE);
-    parent::__construct($storage ?: drupal_container()->get('config.storage'), drupal_container()->get('event_dispatcher'));
-  }
-
-}
diff --git a/core/lib/Drupal/Core/Config/Context/ConfigContext.php b/core/lib/Drupal/Core/Config/Context/ConfigContext.php
index d503beb..2b7ba7f 100644
--- a/core/lib/Drupal/Core/Config/Context/ConfigContext.php
+++ b/core/lib/Drupal/Core/Config/Context/ConfigContext.php
@@ -2,16 +2,14 @@
 
 /**
  * @file
- * Contains Drupal\Core\Config\Context\ConfigContext.
+ * Contains \Drupal\Core\Config\Context\ConfigContext.
  */
 
 namespace Drupal\Core\Config\Context;
 
 use Drupal\Core\Config\Config;
 use Drupal\Core\Config\ConfigEvent;
-use Drupal\Core\Config\ContextInterface;
-use Drupal\Core\Config\StorageInterface;
-use Drupal\Core\KeyValueStore\MemoryStorage;
+use Drupal\Component\Uuid\Uuid;
 use Symfony\Component\EventDispatcher\EventDispatcher;
 
 /**
@@ -20,17 +18,7 @@
  * A configuration context object provides a key/value store that can be used
  * as a parameter to get customized configuration objects.
  */
-class ConfigContext extends MemoryStorage implements ContextInterface {
-
-  /**
-   * Predefined key, will be TRUE for administrative contexts.
-   */
-  const ADMIN = 'config.admin';
-
-  /**
-   * Predefined key, will contain the object type for object contexts.
-   */
-  const OBJECT = 'config.object';
+class ConfigContext implements ContextInterface {
 
   /**
    * Predefined key, values to override specific configuration objects.
@@ -38,44 +26,94 @@ class ConfigContext extends MemoryStorage implements ContextInterface {
   const OVERRIDE = 'config.override';
 
   /**
-   * A storage controller instance for reading and writing configuration data.
+   * The actual storage of key-value pairs.
    *
-   * @var Drupal\Core\Config\StorageInterface
+   * @var array
    */
-  protected $storage;
+  protected $data = array();
 
   /**
    * An event dispatcher instance to use for configuration events.
    *
-   * @var Symfony\Component\EventDispatcher\EventDispatcher
+   * @var \Symfony\Component\EventDispatcher\EventDispatcher
    */
   protected $eventDispatcher;
 
   /**
+   * A unique identifier for the context.
+   *
+   * @var string
+   */
+  protected $uuid;
+
+  /**
    * Constructs the configuration context.
    *
-   * @param \Drupal\Core\Config\StorageInterface $storage
-   *   The storage controller object to use for reading and writing
-   *   configuration data.
-   * @param Symfony\Component\EventDispatcher\EventDispatcher $event_dispatcher
+   * @param \Symfony\Component\EventDispatcher\EventDispatcher $event_dispatcher
    *   An event dispatcher instance to use for configuration events.
    */
-  public function __construct(StorageInterface $storage, EventDispatcher $event_dispatcher) {
-    $this->storage = $storage;
+  public function __construct(EventDispatcher $event_dispatcher) {
     $this->eventDispatcher = $event_dispatcher;
+  }
+
+  /**
+   * Implements Drupal\Core\Config\Context\ContextInterface::init().
+   */
+  public function init($context_key, $data) {
+    if ($data) {
+      $this->set($context_key, $data);
+    }
+    $this->setUuid();
     // Notify event listeners that a configuration context has been created.
     $this->notify('context', NULL);
+    return $this;
+  }
+
+  /**
+   * Implements Drupal\Core\Config\Context\ContextInterface::get().
+   */
+  public function get($key) {
+    return array_key_exists($key, $this->data) ? $this->data[$key] : NULL;
+  }
+
+  /**
+   * Implements Drupal\Core\Config\Context\ContextInterface::set().
+   */
+  public function set($key, $value) {
+    $this->data[$key] = $value;
+  }
+
+  /**
+   * Sets override data.
+   *
+   * @param mixed $data
+   *   Override data to store.
+   *
+   * @return \Drupal\Core\Config\Context\ConfigContext
+   *   The config context object.
+   */
+  public function setOverride($data) {
+    $this->init(self::OVERRIDE, $data);
+    return $this;
+  }
+
+  /**
+   * Implements Drupal\Core\Config\Context\ContextInterface::setUuid().
+   */
+  public function setUuid() {
+    $uuid = new Uuid();
+    $this->uuid = $uuid->generate();
   }
 
   /**
-   * Implements Drupal\Core\Config\ContextInterface::getStorage().
+   * Implements Drupal\Core\Config\Context\ContextInterface::getUuid().
    */
-  public function getStorage() {
-    return $this->storage;
+  public function getUuid() {
+    return $this->uuid;
   }
 
   /**
-   * Implements Drupal\Core\Config\ContextInterface::notify().
+   * Implements Drupal\Core\Config\Context\ContextInterface::notify().
    */
   public function notify($config_event_name, Config $config = NULL) {
     $this->eventDispatcher->dispatch('config.' . $config_event_name, new ConfigEvent($this, $config));
diff --git a/core/lib/Drupal/Core/Config/Context/ConfigContextFactory.php b/core/lib/Drupal/Core/Config/Context/ConfigContextFactory.php
new file mode 100644
index 0000000..a5100d8
--- /dev/null
+++ b/core/lib/Drupal/Core/Config/Context/ConfigContextFactory.php
@@ -0,0 +1,65 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Config\Context\ConfigContextFactory.
+ */
+
+namespace Drupal\Core\Config\Context;
+
+use Drupal\Core\Config\Config;
+use Drupal\Core\Config\StorageInterface;
+use Symfony\Component\EventDispatcher\EventDispatcher;
+
+/**
+ * Defines the base configuration context object.
+ *
+ * A configuration context object provides a key/value store that can be used
+ * as a parameter to get customized configuration objects.
+ */
+class ConfigContextFactory {
+
+  /**
+   * An event dispatcher instance to use for configuration events.
+   *
+   * @var \Symfony\Component\EventDispatcher\EventDispatcher
+   */
+  protected $eventDispatcher;
+
+  /**
+   * Constructs the configuration context.
+   *
+   * @param \Drupal\Core\Config\StorageInterface $storage
+   *   The storage controller object to use for reading and writing
+   *   configuration data.
+   * @param \Symfony\Component\EventDispatcher\EventDispatcher $event_dispatcher
+   *   An event dispatcher instance to use for configuration events.
+   */
+  public function __construct(EventDispatcher $event_dispatcher) {
+    $this->eventDispatcher = $event_dispatcher;
+  }
+
+  /**
+   * Returns a configuration context object.
+   *
+   * @param string $class
+   *   (Optional) The name of the configuration class to use. Defaults to
+   *   Drupal\Core\Config\Context\ConfigContext
+   * @param \Drupal\Core\Config\Context\ContextInterface $context
+   *   (Optional) The configuration context to use.
+   */
+  public function get($class = NULL) {
+    if (!$class) {
+      $class = "Drupal\\Core\\Config\\Context\\ConfigContext";
+    }
+    if (class_exists($class)) {
+      $context = new $class($this->eventDispatcher);
+    }
+    else {
+      throw new \Drupal\Core\Config\ConfigException(sprintf('Unknown config context class: %s', $class));
+    }
+    return $context;
+  }
+
+
+}
diff --git a/core/lib/Drupal/Core/Config/Context/ContextInterface.php b/core/lib/Drupal/Core/Config/Context/ContextInterface.php
new file mode 100644
index 0000000..b3107a7
--- /dev/null
+++ b/core/lib/Drupal/Core/Config/Context/ContextInterface.php
@@ -0,0 +1,88 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Config\Context\ContextInterface.
+ */
+
+namespace Drupal\Core\Config\Context;
+
+use Drupal\Core\Config\Config;
+
+/**
+ * Defines the configuration context interface.
+ *
+ * The configuration context object will contain predefined parameters used
+ * by the configuration object for storage operations and notifications
+ * and contextual data to be used by configuration event listeners.
+ *
+ * @see Drupal\Core\Config\Config
+ * @see Drupal\Core\Config\ConfigFactory
+ * @see config()
+ */
+interface ContextInterface {
+
+  /*
+   * Initialises a config context for use.
+   *
+   * Creates a unique context identifier, adds data and notifies system about
+   * the new context.
+   *
+   * @param string $context_key
+   *   The key that is used to set context data.
+   * @param mixed $data
+   *   The context config data.
+   *
+   * @return \Drupal\Core\Config\Context\ConfigContext
+   *   The config context object.
+   */
+  public function init($context_key, $data);
+
+  /**
+   * Returns the stored value for a given key.
+   *
+   * @param string $key
+   *   The key of the data to retrieve.
+   *
+   * @return mixed
+   *   The stored value, or NULL if no value exists.
+   */
+  public function get($key);
+
+  /**
+   * Saves a value for a given key.
+   *
+   * @param string $key
+   *   The key of the data to store.
+   * @param mixed $value
+   *   The data to store.
+   */
+  public function set($key, $value);
+
+  /**
+   * Sets the uuid for the context.
+   *
+   * @return string
+   *   The context's uuid.
+   */
+  public function setUuid();
+
+  /**
+   * Gets the uuid for the context.
+   *
+   * @return string
+   *   The context's uuid.
+   */
+  public function getUuid();
+
+  /**
+   * Dispatches a config event.
+   *
+   * @param string $config_event_name
+   *   Event name.
+   * @param \Drupal\Core\Config\Config $config
+   *   (optional) Configuration object.
+   */
+  public function notify($config_event_name, Config $config = NULL);
+
+}
diff --git a/core/lib/Drupal/Core/Config/Context/GlobalContext.php b/core/lib/Drupal/Core/Config/Context/GlobalContext.php
deleted file mode 100644
index fb03431..0000000
--- a/core/lib/Drupal/Core/Config/Context/GlobalContext.php
+++ /dev/null
@@ -1,32 +0,0 @@
-<?php
-
-/**
- * @file
- * Contains Drupal\Core\Config\GlobalContext.
- */
-
-namespace Drupal\Core\Config\Context;
-
-use Drupal\Core\Config\StorageInterface;
-use Drupal\Core\KeyValueStore\MemoryStorage;
-use Symfony\Component\EventDispatcher\EventDispatcher;
-
-/**
- * Defines the global configuration context object.
- *
- * This is the regular runtime configuration context that uses configuration
- * overrides from global $conf variable.
- */
-class GlobalContext extends ConfigContext {
-
-  /**
-   * Overrides \Drupal\Core\Config\ConfigContext::__construct().
-   */
-  public function __construct(StorageInterface $storage, EventDispatcher $event_dispatcher) {
-    global $conf;
-
-    $this->data[self::OVERRIDE] = $conf;
-    parent::__construct($storage, $event_dispatcher);
-  }
-
-}
diff --git a/core/lib/Drupal/Core/Config/Context/ObjectContext.php b/core/lib/Drupal/Core/Config/Context/ObjectContext.php
deleted file mode 100644
index 97a5e2b..0000000
--- a/core/lib/Drupal/Core/Config/Context/ObjectContext.php
+++ /dev/null
@@ -1,41 +0,0 @@
-<?php
-
-/**
- * @file
- * Contains Drupal\Core\Config\Context\ObjectContext.
- */
-
-namespace Drupal\Core\Config\Context;
-
-/**
- * Defines a configuration context for some Drupal object.
- *
- * This is a configuration context built around a specific object. They will
- * have the object type under the ConfigContext::TYPE_OBJECT key and the object
- * value under the object type key.
- *
- * For instance for an object with name 'mymodule.myobject' and value $object
- * these are the preset keys and values:
- * - ConfigContext::TYPE_OBJECT, will contain 'mymodule.myobject'
- * - 'mymodule.myobject', will contain the object itself,
- *
- * @see Drupal\user\UserConfigContext
- */
-class ObjectContext extends GlobalContext {
-
-  /**
-   * Overrides \Drupal\Core\Config\ConfigContext::__construct().
-   *
-   * @param string $name
-   *   Object name containing a module name and an object type glued by a dot.
-   * @param mixed $object
-   *   The object value.
-   */
-  public function __construct($name, $object) {
-    // Set the object name for reference.
-    $this->set(self::OBJECT, $name);
-    $this->set($name, $object);
-    parent::__construct(drupal_container()->get('config.storage'), drupal_container()->get('event_dispatcher'));
-  }
-
-}
diff --git a/core/lib/Drupal/Core/Config/ContextInterface.php b/core/lib/Drupal/Core/Config/ContextInterface.php
deleted file mode 100644
index d928bb0..0000000
--- a/core/lib/Drupal/Core/Config/ContextInterface.php
+++ /dev/null
@@ -1,43 +0,0 @@
-<?php
-
-/**
- * @file
- * Contains Drupal\Core\Config\ContextInterface.
- */
-
-namespace Drupal\Core\Config;
-
-use Drupal\Core\KeyValueStore\KeyValueStoreInterface;
-
-/**
- * Defines the configuration context interface.
- *
- * The configuration context object will contain predefined parameters used
- * by the configuration object for storage operations and notifications
- * and contextual data to be used by configuration event listeners.
- *
- * @see Drupal\Core\Config\Config
- * @see Drupal\Core\Config\ConfigFactory
- * @see config()
- */
-interface ContextInterface extends KeyValueStoreInterface {
-
-  /**
-   * Get storage controller.
-   *
-   * @return Drupal\Core\Config\StorageInterface
-   *   A storage controller instance for reading and writing configuration data.
-   */
-  public function getStorage();
-
-  /**
-   * Dispatches a config event.
-   *
-   * @param string $config_event_name
-   *   Event name.
-   * @param \Drupal\Core\Config\Config $config
-   *   (optional) Configuration object.
-   */
-  public function notify($config_event_name, Config $config = NULL);
-
-}
diff --git a/core/lib/Drupal/Core/CoreBundle.php b/core/lib/Drupal/Core/CoreBundle.php
index 3959623..336b1f1 100644
--- a/core/lib/Drupal/Core/CoreBundle.php
+++ b/core/lib/Drupal/Core/CoreBundle.php
@@ -34,6 +34,7 @@ class CoreBundle extends Bundle {
    * Implements \Symfony\Component\HttpKernel\Bundle\BundleInterface::build().
    */
   public function build(ContainerBuilder $container) {
+    global $conf;
 
     // Register active configuration storage.
     $container
@@ -51,11 +52,20 @@ public function build(ContainerBuilder $container) {
       ->addArgument(new Reference('config.cachedstorage.storage'))
       ->addArgument(new Reference('cache.config'));
 
-    $container->register('config.context', 'Drupal\Core\Config\Context\GlobalContext')
-      ->addArgument(new Reference('config.storage'))
+    $container->register('config.context.factory', 'Drupal\Core\Config\Context\ConfigContextFactory')
       ->addArgument(new Reference('event_dispatcher'));
 
+    $container->register('config.context', 'Drupal\Core\Config\Context\ContextInterface')
+      ->setFactoryService(new Reference('config.context.factory'))
+      ->setFactoryMethod('get')
+      ->addMethodCall('setOverride', array($conf));
+
+    $container->register('config.context.admin', 'Drupal\Core\Config\Context\ContextInterface')
+      ->setFactoryService(new Reference('config.context.factory'))
+      ->setFactoryMethod('get');
+
     $container->register('config.factory', 'Drupal\Core\Config\ConfigFactory')
+      ->addArgument(new Reference('config.storage'))
       ->addArgument(new Reference('config.context'))
       ->addTag('persist');
 
diff --git a/core/lib/Drupal/Core/EventSubscriber/ConfigOverrideSubscriber.php b/core/lib/Drupal/Core/EventSubscriber/ConfigOverrideSubscriber.php
index 9678102..376da10 100644
--- a/core/lib/Drupal/Core/EventSubscriber/ConfigOverrideSubscriber.php
+++ b/core/lib/Drupal/Core/EventSubscriber/ConfigOverrideSubscriber.php
@@ -1,14 +1,13 @@
 <?php
 /**
  * @file
- * Contains Drupal\Core\EventSubscriber\ConfigOverrideSubscriber.
+ * Contains \Drupal\Core\EventSubscriber\ConfigOverrideSubscriber.
  */
 
 namespace Drupal\Core\EventSubscriber;
 
 use Drupal\Core\Config\Config;
 use Drupal\Core\Config\ConfigEvent;
-use Drupal\Core\Config\ContextInterface;
 use Drupal\Core\Config\Context\ConfigContext;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 
diff --git a/core/modules/config/lib/Drupal/config/Tests/ConfigLocaleOverride.php b/core/modules/config/lib/Drupal/config/Tests/ConfigLocaleOverride.php
new file mode 100644
index 0000000..2ae344c
--- /dev/null
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigLocaleOverride.php
@@ -0,0 +1,93 @@
+<?php
+
+/**
+ * @file
+ * Definition of \Drupal\config\Tests\ConfigLocaleOverride.
+ */
+
+namespace Drupal\config\Tests;
+
+use Drupal\Core\Language\Language;
+use Drupal\simpletest\DrupalUnitTestBase;
+
+/**
+ * Tests locale config override.
+ */
+class ConfigLocaleOverride extends DrupalUnitTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = array('locale', 'config_test', 'user', 'language', 'system');
+
+  public static function getInfo() {
+    return array(
+      'name' => 'Locale override',
+      'description' => 'Confirm that locale overrides work',
+      'group' => 'Configuration',
+    );
+  }
+
+  public function setUp() {
+    parent::setUp();
+    config_install_default_config('module', 'config_test');
+  }
+
+  /*
+   * Tests basic locale override.
+   */
+  function testConfigLocaleOverride() {
+    $name = 'config_test.system';
+    // Verify the default configuration values exist.
+    $config = config($name);
+    $this->assertIdentical($config->get('foo'), 'en bar');
+  }
+
+  /*
+   * Tests locale override based on user's preferred language.
+   */
+  function testConfigLocaleUserOverride() {
+    $this->installSchema('system', 'variable');
+    $this->installSchema('language', 'language');
+    language_save(new Language(array(
+      'name' => 'French',
+      'langcode' => 'fr',
+    )));
+    language_save(new Language(array(
+      'name' => 'English',
+      'langcode' => 'en',
+    )));
+
+    $this->installSchema('user', 'users');
+    $account = entity_create('user', array(
+      'name' => 'French user',
+      'mail' => 'test@example.com',
+      'created' => REQUEST_TIME,
+      'status' => 1,
+      'preferred_langcode' => 'fr',
+    ));
+
+    $config_context = drupal_container()->get('config.context.user')->setAccount($account);
+    $config = config('config_test.system', $config_context);
+    $this->assertIdentical($config->get('foo'), 'fr bar');
+
+    $account = entity_create('user', array(
+      'name' => 'English user',
+      'mail' => 'test@example.com',
+      'created' => REQUEST_TIME,
+      'status' => 1,
+      'preferred_langcode' => 'en',
+    ));
+    $config_context = drupal_container()->get('config.context.user')->setAccount($account);
+    // Should not have to re-initialise config object to get new overrides as
+    // the new context will have a different uuid.
+    $config = config('config_test.system', $config_context);
+    $this->assertIdentical($config->get('foo'), 'en bar');
+
+    $config = system_config('config_test.system');
+    $this->assertIdentical($config->get('foo'), 'bar');
+  }
+
+}
diff --git a/core/modules/config/lib/Drupal/config/Tests/ConfigOverrideTest.php b/core/modules/config/lib/Drupal/config/Tests/ConfigOverrideTest.php
index f015f82..1dfc9f3 100644
--- a/core/modules/config/lib/Drupal/config/Tests/ConfigOverrideTest.php
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigOverrideTest.php
@@ -53,11 +53,12 @@ function testConfOverride() {
     $this->assertIdentical($config->get('baz'), $expected_original_data['baz']);
     $this->assertIdentical($config->get('404'), $expected_original_data['404']);
 
-    // Apply the overridden data, that needs to be set into the GlobalContext object.
+    // Apply the overridden data, that needs to be set into the config.context
+    // service.
     $conf['config_test.system']['foo'] = 'overridden';
     $conf['config_test.system']['baz'] = 'injected';
     $conf['config_test.system']['404'] = 'derp';
-    drupal_container()->get('config.context')->set(ConfigContext::OVERRIDE, $conf);
+    drupal_container()->get('config.context')->setOverride($conf);
 
     // Verify that the in-memory configuration object still contains the
     // original data.
@@ -95,9 +96,9 @@ function testConfOverride() {
     $this->assertIdentical($config->get('baz'), $conf['config_test.system']['baz']);
     $this->assertIdentical($config->get('404'), $conf['config_test.system']['404']);
 
-    // Remove the $conf overrides and reset value in GlobalContext object.
+    // Remove the $conf overrides and reset value in config.context service.
     unset($conf['config_test.system']);
-    drupal_container()->get('config.context')->set(ConfigContext::OVERRIDE, $conf);
+    drupal_container()->get('config.context')->setOverride($conf);
 
     // Reload it and verify that it still contains the original data.
     $config->init();
diff --git a/core/modules/config/lib/Drupal/config/Tests/LocaleConfigOverride.php b/core/modules/config/lib/Drupal/config/Tests/LocaleConfigOverride.php
deleted file mode 100644
index 20f835d..0000000
--- a/core/modules/config/lib/Drupal/config/Tests/LocaleConfigOverride.php
+++ /dev/null
@@ -1,38 +0,0 @@
-<?php
-
-/**
- * @file
- * Definition of Drupal\config\Tests\LocaleConfigOverride.
- */
-
-namespace Drupal\config\Tests;
-
-use Drupal\simpletest\WebTestBase;
-
-/**
- * Tests locale config override.
- */
-class LocaleConfigOverride extends WebTestBase {
-
-  /**
-   * Modules to enable.
-   *
-   * @var array
-   */
-  public static $modules = array('locale', 'config_test');
-
-  public static function getInfo() {
-    return array(
-      'name' => 'Locale override',
-      'description' => 'Confirm that locale overrides work',
-      'group' => 'Configuration',
-    );
-  }
-
-  function testLocaleConfigOverride() {
-    $name = 'config_test.system';
-    // Verify the default configuration values exist.
-    $config = config($name);
-    $this->assertIdentical($config->get('foo'), 'en bar');
-  }
-}
diff --git a/core/modules/config/tests/config_test/config/locale.config.fr.config_test.system.yml b/core/modules/config/tests/config_test/config/locale.config.fr.config_test.system.yml
new file mode 100644
index 0000000..c36dbf7
--- /dev/null
+++ b/core/modules/config/tests/config_test/config/locale.config.fr.config_test.system.yml
@@ -0,0 +1 @@
+foo: fr bar
diff --git a/core/modules/locale/lib/Drupal/locale/LocaleConfigSubscriber.php b/core/modules/locale/lib/Drupal/locale/LocaleConfigSubscriber.php
index 955641d..79ebbd3 100644
--- a/core/modules/locale/lib/Drupal/locale/LocaleConfigSubscriber.php
+++ b/core/modules/locale/lib/Drupal/locale/LocaleConfigSubscriber.php
@@ -1,14 +1,16 @@
 <?php
 /**
  * @file
- * Definition of Drupal\locale\LocaleConfigSubscriber.
+ * Definition of \Drupal\locale\LocaleConfigSubscriber.
  */
 
 namespace Drupal\locale;
 
 use Drupal\Core\Config\Config;
+use Drupal\Core\Config\Context\ConfigContext;
 use Drupal\Core\Config\ConfigEvent;
 use Drupal\Core\Config\StorageDispatcher;
+use Drupal\Core\Language\Language;
 use Drupal\Core\Language\LanguageManager;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 
@@ -19,6 +21,24 @@
  * $config is always a DrupalConfig object.
  */
 class LocaleConfigSubscriber implements EventSubscriberInterface {
+  /**
+   * The language manager.
+   *
+   * @var \Drupal\Core\Language\LanguageManager
+   */
+  protected $languageManager;
+
+  /**
+   * Constructs a LocaleConfigSubscriber object.
+   *
+   * @param \Drupal\Core\Config\Context\ConfigContext $config_context
+   *   The config context service.
+   * @param \Drupal\Core\Language\LanguageManager $language_manager
+   *   The language manager service.
+   */
+  public function __construct(LanguageManager $language_manager) {
+    $this->languageManager = $language_manager;
+  }
 
   /**
    * Initialize configuration context with language.
@@ -28,18 +48,20 @@ class LocaleConfigSubscriber implements EventSubscriberInterface {
    */
   public function configContext(ConfigEvent $event) {
     $context = $event->getContext();
-    if (!$context->get('locale.language')) {
-      // Add user's language for user context.
-      if ($account = $context->get('user.account')) {
-        $context->set('locale.language', language_load(user_preferred_langcode($account)));
-      }
+
+    // Add user's language for user context.
+    if ($account = $context->get('user.account')) {
+      $context->set('locale.language', language_load(user_preferred_langcode($account)));
+    }
+    elseif ($language = $this->languageManager->getLanguage(LANGUAGE_TYPE_INTERFACE)) {
+      $context->set('locale.language', $language);
     }
   }
 
   /**
    * Override configuration values with localized data.
    *
-   * @param Drupal\Core\Config\ConfigEvent $event
+   * @param \Drupal\Core\Config\ConfigEvent $event
    *   The Event to process.
    */
   public function configLoad(ConfigEvent $event) {
@@ -47,7 +69,9 @@ public function configLoad(ConfigEvent $event) {
     if ($language = $context->get('locale.language')) {
       $config = $event->getConfig();
       $locale_name = $this->getLocaleConfigName($config->getName(), $language);
-      if ($override = $context->getStorage()->read($locale_name)) {
+      // Check to see if the config storage has an appropriately named file
+      // containing override data.
+      if ($override = $event->getConfig()->getStorage()->read($locale_name)) {
         $config->setOverride($override);
       }
     }
@@ -58,8 +82,16 @@ public function configLoad(ConfigEvent $event) {
    *
    * It will be the same name with a prefix depending on language code:
    * locale.config.LANGCODE.NAME
+   *
+   * @param string $name
+   *   The name of the config object.
+   * @param \Drupal\Core\Language\Language $language
+   *   The language object.
+   *
+   * @return string
+   *   The localised config name.
    */
-  public function getLocaleConfigName($name, $language) {
+  public function getLocaleConfigName($name, Language $language) {
     return 'locale.config.' . $language->langcode . '.' . $name;
   }
 
diff --git a/core/modules/locale/locale.module b/core/modules/locale/locale.module
index c0d55d4..b54d76a 100644
--- a/core/modules/locale/locale.module
+++ b/core/modules/locale/locale.module
@@ -16,7 +16,6 @@
 use Drupal\locale\StringDatabaseStorage;
 use Drupal\locale\TranslationsStream;
 use Drupal\Core\Database\Database;
-use Drupal\Core\Config\ConfigFactory;
 
 /**
  * Regular expression pattern used to localize JavaScript strings.
@@ -1308,13 +1307,3 @@ function _locale_rebuild_js($langcode = NULL) {
       return TRUE;
   }
 }
-
-/**
- * Implements hook_language_init().
- */
-function locale_language_init() {
-  // Add current language to default configuration context.
-  drupal_container()->get('config.context')->set('locale.language', language(LANGUAGE_TYPE_INTERFACE));
-  // Add locale helper to configuration subscribers.
-  drupal_container()->get('event_dispatcher')->addSubscriber(new LocaleConfigSubscriber());
-}
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index 41750be..543af6f 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -7,7 +7,6 @@
 
 use Drupal\Core\Utility\ModuleInfo;
 use Drupal\Core\TypedData\Primitive;
-use Drupal\Core\Config\Context\AdminContext;
 use Drupal\system\Plugin\block\block\SystemMenuBlock;
 use Symfony\Component\HttpFoundation\JsonResponse;
 use Symfony\Component\HttpFoundation\Response;
@@ -3463,11 +3462,7 @@ function system_admin_compact_page($mode = 'off') {
  * @see config()
  */
 function system_config($name) {
-  static $context;
-  if (!isset($context)) {
-    $context = new AdminContext('system.config', drupal_container()->get('config.storage'));
-  }
-  return config($name, $context);
+  return config($name, drupal_container()->get('config.context.admin'));
 }
 
 /**
diff --git a/core/modules/user/lib/Drupal/user/UserBundle.php b/core/modules/user/lib/Drupal/user/UserBundle.php
index a4e7d8d..c963bc6 100644
--- a/core/modules/user/lib/Drupal/user/UserBundle.php
+++ b/core/modules/user/lib/Drupal/user/UserBundle.php
@@ -25,5 +25,9 @@ public function build(ContainerBuilder $container) {
     $container
       ->register('user.data', 'Drupal\user\UserData')
       ->addArgument(new Reference('database'));
+    $container->register('config.context.user', 'Drupal\Core\Config\Context\ContextInterface')
+      ->setFactoryService(new Reference('config.context.factory'))
+      ->setFactoryMethod('get')
+      ->addArgument('Drupal\user\UserConfigContext');
   }
 }
diff --git a/core/modules/user/lib/Drupal/user/UserConfigContext.php b/core/modules/user/lib/Drupal/user/UserConfigContext.php
index 2206df7..ed0b957 100644
--- a/core/modules/user/lib/Drupal/user/UserConfigContext.php
+++ b/core/modules/user/lib/Drupal/user/UserConfigContext.php
@@ -2,27 +2,45 @@
 
 /**
  * @file
- * Contains Drupal\user\UserConfigContext
+ * Contains \Drupal\user\UserConfigContext
  */
 
 namespace Drupal\user;
 
-use Drupal\Core\Config\Context\ObjectContext;
+use Drupal\Core\Config\Context\ConfigContext;
 use Drupal\user\Plugin\Core\Entity\User;
 
+
 /**
  * Defines a configuration context object for a user account.
  */
-class UserConfigContext extends ObjectContext {
+class UserConfigContext extends ConfigContext {
+
+  /**
+   * Predefined key for account object.
+   */
+  const USER_KEY = 'user.account';
 
   /**
-   * Overrides \Drupal\Core\Config\ConfigContext::__construct().
+   * Implements \Drupal\Core\Config\Context\ContextInterface::setUuid().
+   */
+  public function setUuid() {
+    // Use the user's uuid to identify the config context.
+    $this->uuid = $this->get(self::USER_KEY)->uuid();
+  }
+
+  /*
+   * Helper function to create config context for user accounts.
+   *
+   * @param \Drupal\user\Plugin\Core\Entity\User $account
+   *   The account to add to the config context.
    *
-   * @param \Drupal\user\Plugin\Core\Entity\User $user
-   *   The user object to use in this context.
+   * @return \Drupal\user\UserConfigContext
+   *   The user config context object.
    */
-  public function __construct($user) {
-    parent::__construct('user.account', $user);
+  public function setAccount(User $account) {
+    $this->init(self::USER_KEY, $account);
+    return $this;
   }
 
 }
diff --git a/core/modules/user/user.module b/core/modules/user/user.module
index 3fa64f2..c5f360c 100644
--- a/core/modules/user/user.module
+++ b/core/modules/user/user.module
@@ -702,18 +702,6 @@ function user_format_name($account) {
 }
 
 /**
- * Implements hook_config_context_info().
- */
-function user_config_context_info() {
-  return array(
-    'user.account' => array(
-      'title' => t('User account'),
-      'class' => '\Drupal\user\UserConfigContext',
-    ),
-  );
-}
-
-/**
  * Implements hook_template_preprocess_default_variables_alter().
  *
  * @see user_user_login()
@@ -1766,17 +1754,14 @@ function user_mail($key, &$message, $params) {
 
   // Get configuration objects customized for this user, that may be localized
   // for the user's language if the locale module is enabled.
-  $config_context = config_factory_set_context(new UserConfigContext($params['account']));
-  $mail_config = config('user.mail');
+  $config_context = drupal_container()->get('config.context.user')->setAccount($params['account']);
+  $mail_config = config('user.mail', $config_context);
 
    // We do not sanitize the token replacement, since the output of this
    // replacement is intended for an e-mail message, not a web browser.
   $token_options = array('langcode' => $langcode, 'callback' => 'user_mail_tokens', 'sanitize' => FALSE, 'clear' => TRUE);
   $message['subject'] .= token_replace($mail_config->get($key . '.subject'), $variables, $token_options);
   $message['body'][] = token_replace($mail_config->get($key . '.body'), $variables, $token_options);
-
-  // Set the configuration context back to the original.
-  config_factory_set_context($config_context);
 }
 
 /**