diff --git a/src/addons/__tests__/renderSubtreeIntoContainer.js b/src/addons/__tests__/renderSubtreeIntoContainer.js
new file mode 100644
index 0000000000..80de6145cf
--- /dev/null
+++ b/src/addons/__tests__/renderSubtreeIntoContainer.js
@@ -0,0 +1,96 @@
+/**
+ * Copyright 2013-2015, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @emails react-core
+ */
+
+'use strict';
+
+var React = require('React');
+var ReactTestUtils = require('ReactTestUtils');
+var renderSubtreeIntoContainer = require('renderSubtreeIntoContainer');
+
+describe('renderSubtreeIntoContainer', function() {
+
+  it('should pass context when rendering subtree elsewhere', function () {
+
+    var portal = document.createElement('div');
+
+    var Component = React.createClass({
+      contextTypes: {
+        foo: React.PropTypes.string.isRequired
+      },
+
+      render: function() {
+        return <div>{this.context.foo}</div>;
+      }
+    });
+
+    var Parent = React.createClass({
+      childContextTypes: {
+        foo: React.PropTypes.string.isRequired,
+      },
+
+      getChildContext: function() {
+        return {
+          foo: 'bar'
+        };
+      },
+
+      render: function() {
+        return null;
+      },
+
+      componentDidMount: function() {
+        expect(function() {
+          renderSubtreeIntoContainer(this, <Component />, portal);
+        }.bind(this)).not.toThrow();
+      }
+    });
+
+    ReactTestUtils.renderIntoDocument(<Parent />);
+    expect(portal.firstChild.innerHTML).toBe('bar');
+  });
+
+  it('should throw if parentComponent is invalid', function () {
+    var portal = document.createElement('div');
+
+    var Component = React.createClass({
+      contextTypes: {
+        foo: React.PropTypes.string.isRequired
+      },
+
+      render: function() {
+        return <div>{this.context.foo}</div>;
+      }
+    });
+
+    var Parent = React.createClass({
+      childContextTypes: {
+        foo: React.PropTypes.string.isRequired,
+      },
+
+      getChildContext: function() {
+        return {
+          foo: 'bar'
+        };
+      },
+
+      render: function() {
+        return null;
+      },
+
+      componentDidMount: function() {
+        expect(function() {
+          renderSubtreeIntoContainer(<Parent />, <Component />, portal);
+        }).toThrow('Invariant Violation: parentComponent' +
+          'must be a valid React Component');
+      }
+    });
+  });
+});
diff --git a/src/addons/renderSubtreeIntoContainer.js b/src/addons/renderSubtreeIntoContainer.js
new file mode 100644
index 0000000000..e145f6e4a1
--- /dev/null
+++ b/src/addons/renderSubtreeIntoContainer.js
@@ -0,0 +1,16 @@
+/**
+ * Copyright 2013-2015, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+* @providesModule renderSubtreeIntoContainer
+*/
+
+'use strict';
+
+var ReactMount = require('ReactMount');
+
+module.exports = ReactMount.renderSubtreeIntoContainer;
diff --git a/src/browser/ReactWithAddons.js b/src/browser/ReactWithAddons.js
index 02c3ca7005..bcf5f06cea 100644
--- a/src/browser/ReactWithAddons.js
+++ b/src/browser/ReactWithAddons.js
@@ -28,6 +28,7 @@ var ReactTransitionGroup = require('ReactTransitionGroup');
 var ReactUpdates = require('ReactUpdates');
 
 var cloneWithProps = require('cloneWithProps');
+var renderSubtreeIntoContainer = require('renderSubtreeIntoContainer');
 var shallowCompare = require('shallowCompare');
 var update = require('update');
 
@@ -40,6 +41,7 @@ React.addons = {
   batchedUpdates: ReactUpdates.batchedUpdates,
   cloneWithProps: cloneWithProps,
   createFragment: ReactFragment.create,
+  renderSubtreeIntoContainer: renderSubtreeIntoContainer,
   shallowCompare: shallowCompare,
   update: update
 };
diff --git a/src/browser/ui/ReactMount.js b/src/browser/ui/ReactMount.js
index 9e64fd86d0..a7afef275f 100644
--- a/src/browser/ui/ReactMount.js
+++ b/src/browser/ui/ReactMount.js
@@ -262,10 +262,12 @@ function mountComponentIntoNode(
     rootID,
     container,
     transaction,
-    shouldReuseMarkup) {
-  var context = emptyObject;
+    shouldReuseMarkup,
+    context) {
   if (__DEV__) {
-    context = {};
+    if (context === emptyObject) {
+      context = {};
+    }
     context[validateDOMNesting.tagStackContextKey] =
       [container.nodeName.toLowerCase()];
   }
@@ -288,7 +290,8 @@ function batchedMountComponentIntoNode(
     componentInstance,
     rootID,
     container,
-    shouldReuseMarkup) {
+    shouldReuseMarkup,
+    context) {
   var transaction = ReactUpdates.ReactReconcileTransaction.getPooled();
   transaction.perform(
     mountComponentIntoNode,
@@ -297,7 +300,8 @@ function batchedMountComponentIntoNode(
     rootID,
     container,
     transaction,
-    shouldReuseMarkup
+    shouldReuseMarkup,
+    context
   );
   ReactUpdates.ReactReconcileTransaction.release(transaction);
 }
@@ -402,7 +406,8 @@ var ReactMount = {
   _renderNewRootComponent: function(
     nextElement,
     container,
-    shouldReuseMarkup
+    shouldReuseMarkup,
+    context
   ) {
     // Various parts of our code (such as ReactCompositeComponent's
     // _renderValidatedComponent) assume that calls to render aren't nested;
@@ -432,7 +437,8 @@ var ReactMount = {
       componentInstance,
       reactRootID,
       container,
-      shouldReuseMarkup
+      shouldReuseMarkup,
+      context
     );
 
     if (__DEV__) {
@@ -451,12 +457,26 @@ var ReactMount = {
    * perform an update on it and only mutate the DOM as necessary to reflect the
    * latest React component.
    *
+   * @param {ReactComponent} parentComponent The conceptual parent of this render tree.
    * @param {ReactElement} nextElement Component element to render.
    * @param {DOMElement} container DOM element to render into.
    * @param {?function} callback function triggered on completion
    * @return {ReactComponent} Component instance rendered in `container`.
    */
-  render: function(nextElement, container, callback) {
+  renderSubtreeIntoContainer: function(parentComponent, nextElement, container, callback) {
+    invariant(
+      parentComponent != null && parentComponent._reactInternalInstance != null,
+      'parentComponent must be a valid React Component'
+    );
+    return ReactMount._renderSubtreeIntoContainer(
+      parentComponent,
+      nextElement,
+      container,
+      callback
+    );
+  },
+
+  _renderSubtreeIntoContainer: function(parentComponent, nextElement, container, callback) {
     invariant(
       ReactElement.isValidElement(nextElement),
       'React.render(): Invalid component element.%s',
@@ -524,11 +544,15 @@ var ReactMount = {
     }
 
     var shouldReuseMarkup = containerHasReactMarkup && !prevComponent;
-
     var component = ReactMount._renderNewRootComponent(
       nextElement,
       container,
-      shouldReuseMarkup
+      shouldReuseMarkup,
+      parentComponent != null ?
+        parentComponent._reactInternalInstance._processChildContext(
+          parentComponent._reactInternalInstance._context
+        ) :
+        emptyObject
     ).getPublicInstance();
     if (callback) {
       callback.call(component);
@@ -536,6 +560,23 @@ var ReactMount = {
     return component;
   },
 
+
+  /**
+   * Renders a React component into the DOM in the supplied `container`.
+   *
+   * If the React component was previously rendered into `container`, this will
+   * perform an update on it and only mutate the DOM as necessary to reflect the
+   * latest React component.
+   *
+   * @param {ReactElement} nextElement Component element to render.
+   * @param {DOMElement} container DOM element to render into.
+   * @param {?function} callback function triggered on completion
+   * @return {ReactComponent} Component instance rendered in `container`.
+   */
+  render: function(nextElement, container, callback) {
+    return ReactMount._renderSubtreeIntoContainer(null, nextElement, container, callback);
+  },
+
   /**
    * Constructs a component instance of `constructor` with `initialProps` and
    * renders it into the supplied `container`.
diff --git a/src/core/ReactDefaultBatchingStrategy.js b/src/core/ReactDefaultBatchingStrategy.js
index 6083799d6e..de856c7762 100644
--- a/src/core/ReactDefaultBatchingStrategy.js
+++ b/src/core/ReactDefaultBatchingStrategy.js
@@ -54,16 +54,16 @@ var ReactDefaultBatchingStrategy = {
    * Call the provided function in a context within which calls to `setState`
    * and friends are batched such that components aren't updated unnecessarily.
    */
-  batchedUpdates: function(callback, a, b, c, d) {
+  batchedUpdates: function(callback, a, b, c, d, e) {
     var alreadyBatchingUpdates = ReactDefaultBatchingStrategy.isBatchingUpdates;
 
     ReactDefaultBatchingStrategy.isBatchingUpdates = true;
 
     // The code is written this way to avoid extra allocations
     if (alreadyBatchingUpdates) {
-      callback(a, b, c, d);
+      callback(a, b, c, d, e);
     } else {
-      transaction.perform(callback, null, a, b, c, d);
+      transaction.perform(callback, null, a, b, c, d, e);
     }
   }
 };
diff --git a/src/core/ReactUpdates.js b/src/core/ReactUpdates.js
index 1c7aea1a13..29ca26641e 100644
--- a/src/core/ReactUpdates.js
+++ b/src/core/ReactUpdates.js
@@ -105,9 +105,9 @@ assign(
 
 PooledClass.addPoolingTo(ReactUpdatesFlushTransaction);
 
-function batchedUpdates(callback, a, b, c, d) {
+function batchedUpdates(callback, a, b, c, d, e) {
   ensureInjected();
-  batchingStrategy.batchedUpdates(callback, a, b, c, d);
+  batchingStrategy.batchedUpdates(callback, a, b, c, d, e);
 }
 
 /**