diff --git a/src/Orchard.Tests.Modules/Orchard.Tests.Modules.csproj b/src/Orchard.Tests.Modules/Orchard.Tests.Modules.csproj
index d4b49b24d..c8e3adf1f 100644
--- a/src/Orchard.Tests.Modules/Orchard.Tests.Modules.csproj
+++ b/src/Orchard.Tests.Modules/Orchard.Tests.Modules.csproj
@@ -59,6 +59,7 @@
       <SpecificVersion>False</SpecificVersion>
       <HintPath>..\..\lib\autofac\Autofac.dll</HintPath>
     </Reference>
+    <Reference Include="Castle.Core, Version=1.1.0.0, Culture=neutral, PublicKeyToken=407dd0808d44fbdc, processorArchitecture=MSIL" />
     <Reference Include="FluentNHibernate, Version=1.0.0.593, Culture=neutral, PublicKeyToken=8aa435e3cb308880, processorArchitecture=MSIL">
       <SpecificVersion>False</SpecificVersion>
       <HintPath>..\..\lib\fluentnhibernate\FluentNHibernate.dll</HintPath>
@@ -127,6 +128,7 @@
     <Compile Include="Roles\Controllers\AdminControllerTests.cs" />
     <Compile Include="Roles\Services\RoleServiceTests.cs" />
     <Compile Include="Settings\Blueprint\ShellDescriptorManagerTests.cs" />
+    <Compile Include="Themes\Services\ThemeServiceTests.cs" />
     <Compile Include="Values.cs" />
     <Compile Include="Users\Controllers\AdminControllerTests.cs" />
     <Compile Include="Users\Services\MembershipServiceTests.cs" />
@@ -148,6 +150,10 @@
       <Project>{C0C45321-B51D-4D8D-9B7B-AA4C2E0B2962}</Project>
       <Name>Orchard.CodeGeneration</Name>
     </ProjectReference>
+    <ProjectReference Include="..\Orchard.Web\Modules\Orchard.Modules\Orchard.Modules.csproj">
+      <Project>{17F86780-9A1F-4AA1-86F1-875EEC2730C7}</Project>
+      <Name>Orchard.Modules</Name>
+    </ProjectReference>
     <ProjectReference Include="..\Orchard.Web\Modules\Orchard.Roles\Orchard.Roles.csproj">
       <Project>{D10AD48F-407D-4DB5-A328-173EC7CB010F}</Project>
       <Name>Orchard.Roles</Name>
@@ -156,6 +162,10 @@
       <Project>{8C7FCBC2-E6E1-405E-BFB5-D8D9E67A09C4}</Project>
       <Name>Orchard.Setup</Name>
     </ProjectReference>
+    <ProjectReference Include="..\Orchard.Web\Modules\Orchard.Themes\Orchard.Themes.csproj">
+      <Project>{CDE24A24-01D3-403C-84B9-37722E18DFB7}</Project>
+      <Name>Orchard.Themes</Name>
+    </ProjectReference>
     <ProjectReference Include="..\Orchard.Web\Modules\Orchard.Users\Orchard.Users.csproj">
       <Project>{79AED36E-ABD0-4747-93D3-8722B042454B}</Project>
       <Name>Orchard.Users</Name>
diff --git a/src/Orchard.Tests.Modules/Themes/Services/ThemeServiceTests.cs b/src/Orchard.Tests.Modules/Themes/Services/ThemeServiceTests.cs
new file mode 100644
index 000000000..141c94613
--- /dev/null
+++ b/src/Orchard.Tests.Modules/Themes/Services/ThemeServiceTests.cs
@@ -0,0 +1,229 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Web;
+using System.Xml.Linq;
+using Autofac;
+using NHibernate;
+using NUnit.Framework;
+using Orchard.Caching;
+using Orchard.ContentManagement;
+using Orchard.ContentManagement.Handlers;
+using Orchard.ContentManagement.MetaData;
+using Orchard.ContentManagement.MetaData.Models;
+using Orchard.ContentManagement.MetaData.Services;
+using Orchard.ContentManagement.Records;
+using Orchard.Core.Settings.Descriptor.Records;
+using Orchard.Core.Settings.Handlers;
+using Orchard.Core.Settings.Metadata;
+using Orchard.Core.Settings.Models;
+using Orchard.Core.Settings.Services;
+using Orchard.Data;
+using Orchard.DisplayManagement;
+using Orchard.DisplayManagement.Descriptors;
+using Orchard.DisplayManagement.Implementation;
+using Orchard.Environment;
+using Orchard.Environment.AutofacUtil.DynamicProxy2;
+using Orchard.Environment.Descriptor;
+using Orchard.Environment.Descriptor.Models;
+using Orchard.Environment.Extensions;
+using Orchard.Environment.Extensions.Models;
+using Orchard.Localization;
+using Orchard.Modules;
+using Orchard.Modules.Services;
+using Orchard.Security;
+using Orchard.Security.Permissions;
+using Orchard.Settings;
+using Orchard.Tests.Stubs;
+using Orchard.Themes;
+using Orchard.Themes.Handlers;
+using Orchard.Themes.Models;
+using Orchard.Themes.Services;
+using Orchard.UI.Notify;
+
+namespace Orchard.Tests.Modules.Themes.Services {
+    [TestFixture]
+    public class ThemeServiceTests {
+        private IThemeService _themeService;
+        private IContainer _container;
+        private ISessionFactory _sessionFactory;
+        private ISession _session;
+
+        [TestFixtureSetUp]
+        public void InitFixture() {
+            var databaseFileName = System.IO.Path.GetTempFileName();
+            _sessionFactory = DataUtility.CreateSessionFactory(databaseFileName,
+                typeof(ThemeSiteSettingsPartRecord),
+                typeof(SiteSettingsPartRecord),
+                typeof(ContentItemVersionRecord),
+                typeof(ContentItemRecord),
+                typeof(ContentTypeRecord));
+        }
+
+        [TestFixtureTearDown]
+        public void TermFixture() { }
+
+        [SetUp]
+        public void Init() {
+            var context = new DynamicProxyContext();
+            var builder = new ContainerBuilder();
+            builder.RegisterModule(new SettingsModule());
+            builder.RegisterType<ThemeService>().EnableDynamicProxy(context).As<IThemeService>();
+            builder.RegisterType<SettingsModuleInterceptor>().As<ISettingsModuleInterceptor>();
+            builder.RegisterType<SiteService>().As<ISiteService>();
+            builder.RegisterGeneric(typeof(Repository<>)).As(typeof(IRepository<>));
+            builder.RegisterType<DefaultContentManager>().As<IContentManager>();
+            builder.RegisterType<StubCacheManager>().As<ICacheManager>();
+            builder.RegisterType<ContentDefinitionManager>().As<IContentDefinitionManager>();
+            builder.RegisterType<DefaultContentManagerSession>().As<IContentManagerSession>();
+            builder.RegisterType<ShapeHelperFactory>().As<IShapeHelperFactory>();
+            builder.RegisterType<DefaultShapeFactory>().As<IShapeFactory>();
+            builder.RegisterType<DefaultShapeTableManager>().As<IShapeTableManager>();
+            builder.RegisterType<StubExtensionManager>().As<IExtensionManager>();
+            builder.RegisterType<DefaultContentQuery>().As<IContentQuery>();
+            builder.RegisterType<SiteSettingsPartHandler>().As<IContentHandler>();
+            builder.RegisterType<ThemeSiteSettingsPartHandler>().As<IContentHandler>();
+            builder.RegisterType<ModuleService>().As<IModuleService>();
+            builder.RegisterType<OrchardServices>().As<IOrchardServices>();
+            builder.RegisterType<StubShellDescriptorManager>().As<IShellDescriptorManager>();
+            builder.RegisterType<TransactionManager>().As<ITransactionManager>();
+            builder.RegisterType<Notifier>().As<INotifier>();
+            builder.RegisterType<StubAuthorizer>().As<IAuthorizer>();
+            builder.RegisterType(typeof(SettingsFormatter))
+                .As(typeof(IMapper<XElement, SettingsDictionary>))
+                .As(typeof(IMapper<SettingsDictionary, XElement>));
+            _session = _sessionFactory.OpenSession();
+            builder.RegisterInstance(new TestSessionLocator(_session)).As<ISessionLocator>();
+            _container = builder.Build();
+            _themeService = _container.Resolve<IThemeService>();
+        }
+
+        //todo: test theme feature enablement
+
+        [Test]
+        public void ThemeWithNoBaseThemeCanBeSetAsSiteTheme() {
+            _themeService.SetSiteTheme("ThemeOne");
+            var siteTheme = _themeService.GetSiteTheme();
+            Assert.That(siteTheme.ThemeName, Is.EqualTo("ThemeOne"));
+        }
+
+        [Test]
+        public void ThemeWithAvailableBaseThemeCanBeSetAsSiteTheme() {
+            _themeService.SetSiteTheme("ThemeTwo");
+            var siteTheme = _themeService.GetSiteTheme();
+            Assert.That(siteTheme.ThemeName, Is.EqualTo("ThemeTwo"));
+            Assert.That(siteTheme.BaseTheme, Is.EqualTo("ThemeOne"));
+        }
+
+        [Test]
+        public void ThemeWithUnavailableBaseThemeCanBeSetAsSiteTheme() {
+            _themeService.SetSiteTheme("ThemeOne");
+            _themeService.SetSiteTheme("ThemeThree");
+            var siteTheme = _themeService.GetSiteTheme();
+            Assert.That(siteTheme.ThemeName, Is.EqualTo("ThemeOne"));
+        }
+
+        #region Stubs
+
+        public class TestSessionLocator : ISessionLocator {
+            private readonly ISession _session;
+
+            public TestSessionLocator(ISession session) {
+                _session = session;
+            }
+
+            public ISession For(Type entityType) {
+                return _session;
+            }
+        }
+
+        public class StubAuthorizer : IAuthorizer {
+            public bool Authorize(Permission permission) {
+                return true;
+            }
+            public bool Authorize(Permission permission, LocalizedString message) {
+                return true;
+            }
+            public bool Authorize(Permission permission, IContent content, LocalizedString message) {
+                return true;
+            }
+        }
+
+        public class StubExtensionManager : IExtensionManager {
+            public IEnumerable<ExtensionDescriptor> AvailableExtensions() {
+                var extensions = new[] {
+                    new ExtensionDescriptor {Name = "ThemeOne", ExtensionType = "Theme"},
+                    new ExtensionDescriptor {Name = "ThemeTwo", BaseTheme = "ThemeOne", ExtensionType = "Theme"},
+                    new ExtensionDescriptor {Name = "ThemeThree", BaseTheme = "TheThemeThatIsntThere", ExtensionType = "Theme"},
+                };
+
+                foreach (var extension in extensions) {
+                    extension.Features = new[] { new FeatureDescriptor { Extension = extension, Name = extension.Name } };
+                    yield return extension;
+                }
+            }
+
+            public IEnumerable<FeatureDescriptor> AvailableFeatures() {
+                return AvailableExtensions().SelectMany(ed => ed.Features);
+            }
+
+            public IEnumerable<Feature> LoadFeatures(IEnumerable<FeatureDescriptor> featureDescriptors) {
+                return featureDescriptors.Select(FrameworkFeature);
+            }
+
+            private static Feature FrameworkFeature(FeatureDescriptor descriptor) {
+                return new Feature {
+                    Descriptor = descriptor
+                };
+            }
+
+            public void InstallExtension(string extensionType, HttpPostedFileBase extensionBundle) {
+                throw new NotImplementedException();
+            }
+
+            public void UninstallExtension(string extensionType, string extensionName) {
+                throw new NotImplementedException();
+            }
+
+            public void Monitor(Action<IVolatileToken> monitor) {
+                throw new NotImplementedException();
+            }
+        }
+
+        public class StubShellDescriptorManager : IShellDescriptorManager {
+            private readonly ShellDescriptorRecord _shellDescriptorRecord = new ShellDescriptorRecord();
+            public ShellDescriptor GetShellDescriptor() {
+                return GetShellDescriptorFromRecord(_shellDescriptorRecord);
+            }
+
+            public void UpdateShellDescriptor(int priorSerialNumber, IEnumerable<ShellFeature> enabledFeatures, IEnumerable<ShellParameter> parameters) {
+                _shellDescriptorRecord.Features.Clear();
+                foreach (var feature in enabledFeatures) {
+                    _shellDescriptorRecord.Features.Add(new ShellFeatureRecord { Name = feature.Name, ShellDescriptorRecord = null });
+                }
+
+                _shellDescriptorRecord.Parameters.Clear();
+                foreach (var parameter in parameters) {
+                    _shellDescriptorRecord.Parameters.Add(new ShellParameterRecord {
+                        Component = parameter.Component,
+                        Name = parameter.Name,
+                        Value = parameter.Value,
+                        ShellDescriptorRecord = null
+                    });
+                }
+            }
+
+            private static ShellDescriptor GetShellDescriptorFromRecord(ShellDescriptorRecord shellDescriptorRecord) {
+                return new ShellDescriptor {
+                    SerialNumber = shellDescriptorRecord.SerialNumber,
+                    Features = shellDescriptorRecord.Features.Select(descriptorFeatureRecord => new ShellFeature {Name = descriptorFeatureRecord.Name}).ToList(),
+                    Parameters = shellDescriptorRecord.Parameters.Select(descriptorParameterRecord => new ShellParameter {
+                        Component = descriptorParameterRecord.Component, Name = descriptorParameterRecord.Name, Value = descriptorParameterRecord.Value
+                    }).ToList()
+                };
+            }
+        }
+
+        #endregion
+    }
+}
\ No newline at end of file
diff --git a/src/Orchard.Tests/DisplayManagement/DefaultDisplayManagerTests.cs b/src/Orchard.Tests/DisplayManagement/DefaultDisplayManagerTests.cs
index dee0f004e..388086e3c 100644
--- a/src/Orchard.Tests/DisplayManagement/DefaultDisplayManagerTests.cs
+++ b/src/Orchard.Tests/DisplayManagement/DefaultDisplayManagerTests.cs
@@ -1,7 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.Linq;
-using System.Text;
 using System.Web;
 using System.Web.Mvc;
 using Autofac;
@@ -10,7 +8,6 @@ using NUnit.Framework;
 using Orchard.DisplayManagement.Descriptors;
 using Orchard.DisplayManagement.Implementation;
 using Orchard.DisplayManagement.Shapes;
-using Orchard.Tests.Stubs;
 using Orchard.Themes;
 
 namespace Orchard.Tests.DisplayManagement {
@@ -42,6 +39,7 @@ namespace Orchard.Tests.DisplayManagement {
             public string HomePage { get; set; }
             public string Tags { get; set; }
             public string Zones { get; set; }
+            public string BaseTheme { get; set; }
         }
 
 
diff --git a/src/Orchard.Web/Modules/Orchard.Setup/SetupMode.cs b/src/Orchard.Web/Modules/Orchard.Setup/SetupMode.cs
index 362b3d0ce..5fd304468 100644
--- a/src/Orchard.Web/Modules/Orchard.Setup/SetupMode.cs
+++ b/src/Orchard.Web/Modules/Orchard.Setup/SetupMode.cs
@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.Web;
-using System.Web.Mvc;
 using System.Web.Routing;
 using Autofac;
 using Orchard.Commands;
@@ -9,7 +8,6 @@ using Orchard.Commands.Builtin;
 using Orchard.ContentManagement;
 using Orchard.ContentManagement.Handlers;
 using Orchard.ContentManagement.MetaData.Builders;
-using Orchard.Core.Shapes;
 using Orchard.Data.Migration.Interpreters;
 using Orchard.Data.Providers;
 using Orchard.Data.Migration;
@@ -18,13 +16,10 @@ using Orchard.DisplayManagement.Descriptors;
 using Orchard.DisplayManagement.Descriptors.ShapeAttributeStrategy;
 using Orchard.DisplayManagement.Descriptors.ShapeTemplateStrategy;
 using Orchard.DisplayManagement.Implementation;
-using Orchard.DisplayManagement.Shapes;
 using Orchard.Environment;
-using Orchard.Environment.Extensions;
 using Orchard.Environment.Extensions.Models;
 using Orchard.Localization;
 using Orchard.Mvc;
-using Orchard.Mvc.Filters;
 using Orchard.Mvc.ModelBinders;
 using Orchard.Mvc.Routes;
 using Orchard.Mvc.ViewEngines;
@@ -116,6 +111,7 @@ namespace Orchard.Setup {
                 public string HomePage { get; set; }
                 public string Tags { get; set; }
                 public string Zones { get; set; }
+                public string BaseTheme { get; set; }
             }
 
             private readonly SafeModeTheme _theme = new SafeModeTheme {
diff --git a/src/Orchard.Web/Modules/Orchard.Themes/Models/Theme.cs b/src/Orchard.Web/Modules/Orchard.Themes/Models/Theme.cs
index 6b5b2f8f0..70f24ec98 100644
--- a/src/Orchard.Web/Modules/Orchard.Themes/Models/Theme.cs
+++ b/src/Orchard.Web/Modules/Orchard.Themes/Models/Theme.cs
@@ -8,5 +8,6 @@
         public string HomePage { get; set; }
         public string Tags { get; set; }
         public string Zones { get; set; }
+        public string BaseTheme { get; set; }
     }
 }
\ No newline at end of file
diff --git a/src/Orchard.Web/Modules/Orchard.Themes/Services/ThemeService.cs b/src/Orchard.Web/Modules/Orchard.Themes/Services/ThemeService.cs
index c8b4ea08b..c8def13a6 100644
--- a/src/Orchard.Web/Modules/Orchard.Themes/Services/ThemeService.cs
+++ b/src/Orchard.Web/Modules/Orchard.Themes/Services/ThemeService.cs
@@ -33,9 +33,9 @@ namespace Orchard.Themes.Services {
         protected virtual ISite CurrentSite { get; [UsedImplicitly] private set; }
 
         public ITheme GetSiteTheme() {
-            string currentThemeName = CurrentSite.As<ThemeSiteSettingsPart>().Record.CurrentThemeName;
+            string currentThemeName = CurrentSite.As<ThemeSiteSettingsPart>().CurrentThemeName;
 
-            if (String.IsNullOrEmpty(currentThemeName)) {
+            if (string.IsNullOrEmpty(currentThemeName)) {
                 return null;
             }
 
@@ -43,24 +43,35 @@ namespace Orchard.Themes.Services {
         }
 
         public void SetSiteTheme(string themeName) {
-            if (GetThemeByName(themeName) != null) {
+            if (string.IsNullOrWhiteSpace(themeName))
+                return;
 
-                var currentTheme = CurrentSite.As<ThemeSiteSettingsPart>().Record.CurrentThemeName;
+            //todo: (heskew) need messages given in addition to all of these early returns so something meaningful can be presented to the user
+            var themeToSet = GetThemeByName(themeName);
+            if (themeToSet == null)
+                return;
 
-                if ( !String.IsNullOrEmpty(currentTheme) ) {
-                    _moduleService.DisableFeatures(new[] {currentTheme}, true);
-                }
-
-                if ( !String.IsNullOrEmpty(themeName) ) {
-                    _moduleService.EnableFeatures(new[] {themeName}, true);
-                }
-
-                CurrentSite.As<ThemeSiteSettingsPart>().Record.CurrentThemeName = themeName;
+            //if there's a base theme, it needs to be present
+            ITheme baseTheme = null;
+            if (!string.IsNullOrWhiteSpace(themeToSet.BaseTheme)) {
+                baseTheme = GetThemeByName(themeToSet.BaseTheme);
+                if (baseTheme == null)
+                    return;
             }
+
+            var currentTheme = CurrentSite.As<ThemeSiteSettingsPart>().CurrentThemeName;
+            if ( !string.IsNullOrEmpty(currentTheme) )
+                _moduleService.DisableFeatures(new[] {currentTheme}, true);
+
+            if (baseTheme != null)
+                _moduleService.EnableFeatures(new[] {themeToSet.BaseTheme});
+
+            _moduleService.EnableFeatures(new[] {themeToSet.ThemeName}, true);
+
+            CurrentSite.As<ThemeSiteSettingsPart>().Record.CurrentThemeName = themeToSet.ThemeName;
         }
 
         public ITheme GetRequestTheme(RequestContext requestContext) {
-
             var requestTheme = _themeSelectors
                 .Select(x => x.GetTheme(requestContext))
                 .Where(x => x != null)
@@ -80,7 +91,7 @@ namespace Orchard.Themes.Services {
 
         public ITheme GetThemeByName(string name) {
             foreach (var descriptor in _extensionManager.AvailableExtensions()) {
-                if (String.Equals(descriptor.Name, name, StringComparison.OrdinalIgnoreCase)) {
+                if (string.Equals(descriptor.Name, name, StringComparison.OrdinalIgnoreCase)) {
                     return CreateTheme(descriptor);
                 }
             }
@@ -91,11 +102,10 @@ namespace Orchard.Themes.Services {
         /// Loads only enabled themes
         /// </summary>
         public IEnumerable<ITheme> GetInstalledThemes() {
-
             var themes = new List<ITheme>();
             foreach (var descriptor in _extensionManager.AvailableExtensions()) {
-                
-                if (!String.Equals(descriptor.ExtensionType, "Theme", StringComparison.OrdinalIgnoreCase)) {
+
+                if (!string.Equals(descriptor.ExtensionType, "Theme", StringComparison.OrdinalIgnoreCase)) {
                     continue;
                 }
 
@@ -116,16 +126,17 @@ namespace Orchard.Themes.Services {
             _extensionManager.UninstallExtension("Theme", themeName);
         }
 
-        private ITheme CreateTheme(ExtensionDescriptor descriptor) {
+        private static ITheme CreateTheme(ExtensionDescriptor descriptor) {
             return new Theme {
-                Author = descriptor.Author ?? String.Empty,
-                Description = descriptor.Description ?? String.Empty,
-                DisplayName = descriptor.DisplayName ?? String.Empty,
-                HomePage = descriptor.WebSite ?? String.Empty,
+                Author = descriptor.Author ?? "",
+                Description = descriptor.Description ?? "",
+                DisplayName = descriptor.DisplayName ?? "",
+                HomePage = descriptor.WebSite ?? "",
                 ThemeName = descriptor.Name,
-                Version = descriptor.Version ?? String.Empty,
-                Tags = descriptor.Tags ?? String.Empty,
-                Zones = descriptor.Zones ?? String.Empty,
+                Version = descriptor.Version ?? "",
+                Tags = descriptor.Tags ?? "",
+                Zones = descriptor.Zones ?? "",
+                BaseTheme = descriptor.BaseTheme ?? "",
             };
         }
     }
diff --git a/src/Orchard/Environment/Extensions/Folders/ExtensionFolders.cs b/src/Orchard/Environment/Extensions/Folders/ExtensionFolders.cs
index 7bf74cdcf..726d8099d 100644
--- a/src/Orchard/Environment/Extensions/Folders/ExtensionFolders.cs
+++ b/src/Orchard/Environment/Extensions/Folders/ExtensionFolders.cs
@@ -127,6 +127,7 @@ namespace Orchard.Environment.Extensions.Folders {
                 Tags = GetValue(fields, "tags"),
                 AntiForgery = GetValue(fields, "antiforgery"),
                 Zones = GetValue(fields, "zones"),
+                BaseTheme = GetValue(fields, "basetheme"),
             };
 
             extensionDescriptor.Features = GetFeaturesForExtension(GetMapping(fields, "features"), extensionDescriptor);
diff --git a/src/Orchard/Environment/Extensions/Models/ExtensionDescriptor.cs b/src/Orchard/Environment/Extensions/Models/ExtensionDescriptor.cs
index ec8a96347..667b8ab1e 100644
--- a/src/Orchard/Environment/Extensions/Models/ExtensionDescriptor.cs
+++ b/src/Orchard/Environment/Extensions/Models/ExtensionDescriptor.cs
@@ -27,6 +27,7 @@ namespace Orchard.Environment.Extensions.Models {
         public string Tags { get; set; }
         public string AntiForgery { get; set; }
         public string Zones { get; set; }
+        public string BaseTheme { get; set; }
 
         public IEnumerable<FeatureDescriptor> Features { get; set; }
     }
diff --git a/src/Orchard/Themes/ITheme.cs b/src/Orchard/Themes/ITheme.cs
index b144049d6..178a651e6 100644
--- a/src/Orchard/Themes/ITheme.cs
+++ b/src/Orchard/Themes/ITheme.cs
@@ -11,5 +11,6 @@
         string HomePage { get; set; }
         string Tags { get; set; }
         string Zones { get; set; }
+        string BaseTheme { get; set; }
     }
 }