diff --git a/src/Umbraco.Core/Models/IContent.cs b/src/Umbraco.Core/Models/IContent.cs
new file mode 100644
index 0000000000..b391c62e7e
--- /dev/null
+++ b/src/Umbraco.Core/Models/IContent.cs
@@ -0,0 +1,56 @@
+using System;
+
+namespace Umbraco.Core.Models
+{
+    /// <summary>
+    /// Defines a Content object
+    /// </summary>
+    public interface IContent : IContentBase
+    {
+        /// <summary>
+        /// Alias of the template used by the Content
+        /// This is used to override the default one from the ContentType
+        /// </summary>
+        string Template { get; set; }
+
+        /// <summary>
+        /// Boolean indicating whether the Content is Published or not
+        /// </summary>
+        bool Published { get; }
+
+        /// <summary>
+        /// Language of the data contained within the Content object
+        /// </summary>
+        string Language { get; set; }
+
+        /// <summary>
+        /// Gets the Guid Id of the Content's Version
+        /// </summary>
+        Guid Version { get; }
+
+        /// <summary>
+        /// Gets or Sets the date the Content should be released and thus be published
+        /// </summary>
+        DateTime? ReleaseDate { get; set; }
+
+        /// <summary>
+        /// Gets or Sets the date the Content should expire and thus be unpublished
+        /// </summary>
+        DateTime? ExpireDate { get; set; }
+
+        /// <summary>
+        /// Changes the <see cref="IContentType"/> for the current content object
+        /// </summary>
+        /// <param name="contentType">New ContentType for this content</param>
+        /// <remarks>Leaves PropertyTypes intact after change</remarks>
+        void ChangeContentType(IContentType contentType);
+
+        /// <summary>
+        /// Changes the <see cref="IContentType"/> for the current content object and removes PropertyTypes,
+        /// which are not part of the new ContentType.
+        /// </summary>
+        /// <param name="contentType">New ContentType for this content</param>
+        /// <param name="clearProperties">Boolean indicating whether to clear PropertyTypes upon change</param>
+        void ChangeContentType(IContentType contentType, bool clearProperties);
+    }
+}
\ No newline at end of file
diff --git a/src/Umbraco.Core/Models/IContentBase.cs b/src/Umbraco.Core/Models/IContentBase.cs
new file mode 100644
index 0000000000..99d42b5828
--- /dev/null
+++ b/src/Umbraco.Core/Models/IContentBase.cs
@@ -0,0 +1,105 @@
+using System.Collections.Generic;
+using Umbraco.Core.Models.EntityBase;
+
+namespace Umbraco.Core.Models
+{
+    /// <summary>
+    /// Defines the base for a Content object with properties that
+    /// are shared between Content and Media.
+    /// </summary>
+    public interface IContentBase : IAggregateRoot
+    {
+        /// <summary>
+        /// Gets or Sets the Id of the Parent for the Content
+        /// </summary>
+        int ParentId { get; set; }
+
+        /// <summary>
+        /// Gets or Sets the Name of the Content
+        /// </summary>
+        string Name { get; set; }
+
+        /// <summary>
+        /// Gets the Url name of the Content
+        /// </summary>
+        string UrlName { get; }
+
+        /// <summary>
+        /// Gets or Sets the Sort Order of the Content
+        /// </summary>
+        int SortOrder { get; set; }
+
+        /// <summary>
+        /// Gets or Sets the Level of the Content
+        /// </summary>
+        int Level { get; set; }
+
+        /// <summary>
+        /// Gets or Sets the Path of the Content
+        /// </summary>
+        string Path { get; set; }
+
+        /// <summary>
+        /// Id of the user who created the Content
+        /// </summary>
+        int UserId { get; set; }
+
+        /// <summary>
+        /// Boolean indicating whether this Content is Trashed or not.
+        /// If Content is Trashed it will be located in the Recyclebin.
+        /// </summary>
+        bool Trashed { get; }
+        
+        /// <summary>
+        /// Integer Id of the default ContentType
+        /// </summary>
+        int ContentTypeId { get; }
+
+        /// <summary>
+        /// List of properties, which make up all the data available for this Content object
+        /// </summary>
+        /// <remarks>Properties are loaded as part of the Content object graph</remarks>
+        PropertyCollection Properties { get; set; }
+
+        /// <summary>
+        /// List of PropertyGroups available on this Content object
+        /// </summary>
+        /// <remarks>PropertyGroups are kind of lazy loaded as part of the object graph</remarks>
+        IEnumerable<PropertyGroup> PropertyGroups { get; }
+
+        /// <summary>
+        /// List of PropertyTypes available on this Content object
+        /// </summary>
+        /// <remarks>PropertyTypes are kind of lazy loaded as part of the object graph</remarks>
+        IEnumerable<PropertyType> PropertyTypes { get; }
+
+        /// <summary>
+        /// Indicates whether the content object has a property with the supplied alias
+        /// </summary>
+        /// <param name="propertyTypeAlias">Alias of the PropertyType</param>
+        /// <returns>True if Property with given alias exists, otherwise False</returns>
+        bool HasProperty(string propertyTypeAlias);
+
+        /// <summary>
+        /// Gets the value of a Property
+        /// </summary>
+        /// <param name="propertyTypeAlias">Alias of the PropertyType</param>
+        /// <returns><see cref="Property"/> Value as an <see cref="object"/></returns>
+        object GetValue(string propertyTypeAlias);
+
+        /// <summary>
+        /// Gets the value of a Property
+        /// </summary>
+        /// <typeparam name="TPassType">Type of the value to return</typeparam>
+        /// <param name="propertyTypeAlias">Alias of the PropertyType</param>
+        /// <returns><see cref="Property"/> Value as a <see cref="TPassType"/></returns>
+        TPassType GetValue<TPassType>(string propertyTypeAlias);
+
+        /// <summary>
+        /// Sets the value of a Property
+        /// </summary>
+        /// <param name="propertyTypeAlias">Alias of the PropertyType</param>
+        /// <param name="value">Value to set for the Property</param>
+        void SetValue(string propertyTypeAlias, object value);
+    }
+}
\ No newline at end of file
diff --git a/src/Umbraco.Core/Models/IContentType.cs b/src/Umbraco.Core/Models/IContentType.cs
new file mode 100644
index 0000000000..3d9282278d
--- /dev/null
+++ b/src/Umbraco.Core/Models/IContentType.cs
@@ -0,0 +1,20 @@
+using System.Collections.Generic;
+
+namespace Umbraco.Core.Models
+{
+    /// <summary>
+    /// Defines a ContentType, which Content is based on
+    /// </summary>
+    public interface IContentType : IContentTypeComposition
+    {
+        /// <summary>
+        /// Gets or Sets the path to the default Template of the ContentType
+        /// </summary>
+        string DefaultTemplate { get; set; }
+
+        /// <summary>
+        /// Gets or Sets a list of Template names/paths which are allowed for the ContentType
+        /// </summary>
+        IEnumerable<string> AllowedTemplates { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/src/Umbraco.Core/Models/IContentTypeBase.cs b/src/Umbraco.Core/Models/IContentTypeBase.cs
new file mode 100644
index 0000000000..93ad407db6
--- /dev/null
+++ b/src/Umbraco.Core/Models/IContentTypeBase.cs
@@ -0,0 +1,77 @@
+using System.Collections.Generic;
+using Umbraco.Core.Models.EntityBase;
+
+namespace Umbraco.Core.Models
+{
+    /// <summary>
+    /// Defines the base for a ContentType with properties that
+    /// are shared between ContentTypes and MediaTypes.
+    /// </summary>
+    public interface IContentTypeBase : IAggregateRoot
+    {
+        /// <summary>
+        /// Gets or Sets the Alias of the ContentType
+        /// </summary>
+        string Alias { get; set; }
+
+        /// <summary>
+        /// Gets or Sets the Name of the ContentType
+        /// </summary>
+        string Name { get; set; }
+
+        /// <summary>
+        /// Gets or Sets the Id of Parent of the ContentType
+        /// </summary>
+        int ParentId { get; set; }
+
+        /// <summary>
+        /// Gets or Sets the Level of the Content
+        /// </summary>
+        int Level { get; set; }
+
+        /// <summary>
+        /// Gets or Sets the Path of the Content
+        /// </summary>
+        string Path { get; set; }
+
+        /// <summary>
+        /// Gets or Sets the Description for the ContentType
+        /// </summary>
+        string Description { get; set; }
+
+        /// <summary>
+        /// Gets or Sets the Sort Order of the ContentType
+        /// </summary>
+        int SortOrder { get; set; }
+
+        /// <summary>
+        /// Gets or Sets the Icon for the ContentType
+        /// </summary>
+        string Icon { get; set; }
+
+        /// <summary>
+        /// Gets or Sets the Thumbnail for the ContentType
+        /// </summary>
+        string Thumbnail { get; set; }
+
+        /// <summary>
+        /// Gets or Sets the Id of the User who created the ContentType
+        /// </summary>
+        int UserId { get; set; }
+
+        /// <summary>
+        /// Gets or Sets a list of integer Ids of the ContentTypes allowed under the ContentType
+        /// </summary>
+        IEnumerable<int> AllowedContentTypes { get; set; }
+
+        /// <summary>
+        /// Gets or Sets a collection of Property Groups
+        /// </summary>
+        PropertyGroupCollection PropertyGroups { get; set; }
+
+        /// <summary>
+        /// Gets an enumerable list of Property Types aggregated for all groups
+        /// </summary>
+        IEnumerable<PropertyType> PropertyTypes { get; } 
+    }
+}
\ No newline at end of file
diff --git a/src/Umbraco.Core/Models/IContentTypeComposition.cs b/src/Umbraco.Core/Models/IContentTypeComposition.cs
new file mode 100644
index 0000000000..5e97d75e6c
--- /dev/null
+++ b/src/Umbraco.Core/Models/IContentTypeComposition.cs
@@ -0,0 +1,52 @@
+using System.Collections.Generic;
+
+namespace Umbraco.Core.Models
+{
+    /// <summary>
+    /// Defines the Composition of a ContentType
+    /// </summary>
+    public interface IContentTypeComposition : IContentTypeBase
+    {
+        /// <summary>
+        /// Gets a list of ContentTypes that make up a composition of PropertyGroups and PropertyTypes for the current ContentType
+        /// </summary>
+        List<IContentTypeComposition> ContentTypeComposition { get; }
+
+        /// <summary>
+        /// Gets a list of <see cref="PropertyGroup"/> objects from the composition
+        /// </summary>
+        IEnumerable<PropertyGroup> CompositionPropertyGroups { get; }
+
+        /// <summary>
+        /// Gets a list of <see cref="PropertyType"/> objects from the composition
+        /// </summary>
+        IEnumerable<PropertyType> CompositionPropertyTypes { get; }
+
+        /// <summary>
+        /// Adds a new ContentType to the list of composite ContentTypes
+        /// </summary>
+        /// <param name="contentType"><see cref="IContentType"/> to add</param>
+        /// <returns>True if ContentType was added, otherwise returns False</returns>
+        bool AddContentType(IContentTypeComposition contentType);
+
+        /// <summary>
+        /// Removes a ContentType with the supplied alias from the the list of composite ContentTypes
+        /// </summary>
+        /// <param name="alias">Alias of a <see cref="IContentType"/></param>
+        /// <returns>True if ContentType was removed, otherwise returns False</returns>
+        bool RemoveContentType(string alias);
+
+        /// <summary>
+        /// Checks if a ContentType with the supplied alias exists in the list of composite ContentTypes
+        /// </summary>
+        /// <param name="alias">Alias of a <see cref="IContentType"/></param>
+        /// <returns>True if ContentType with alias exists, otherwise returns False</returns>
+        bool ContentTypeCompositionExists(string alias);
+
+        /// <summary>
+        /// Gets a list of ContentType aliases from the current composition 
+        /// </summary>
+        /// <returns></returns>
+        IEnumerable<string> CompositionAliases();
+    }
+}
\ No newline at end of file
diff --git a/src/Umbraco.Core/Models/IMedia.cs b/src/Umbraco.Core/Models/IMedia.cs
new file mode 100644
index 0000000000..1f1e2c78c7
--- /dev/null
+++ b/src/Umbraco.Core/Models/IMedia.cs
@@ -0,0 +1,20 @@
+namespace Umbraco.Core.Models
+{
+    public interface IMedia : IContentBase
+    {
+        /// <summary>
+        /// Changes the <see cref="IMediaType"/> for the current content object
+        /// </summary>
+        /// <param name="contentType">New ContentType for this content</param>
+        /// <remarks>Leaves PropertyTypes intact after change</remarks>
+        void ChangeContentType(IMediaType contentType);
+
+        /// <summary>
+        /// Changes the <see cref="IMediaType"/> for the current content object and removes PropertyTypes,
+        /// which are not part of the new ContentType.
+        /// </summary>
+        /// <param name="contentType">New ContentType for this content</param>
+        /// <param name="clearProperties">Boolean indicating whether to clear PropertyTypes upon change</param>
+        void ChangeContentType(IMediaType contentType, bool clearProperties);
+    }
+}
\ No newline at end of file
diff --git a/src/Umbraco.Core/Models/IMediaType.cs b/src/Umbraco.Core/Models/IMediaType.cs
new file mode 100644
index 0000000000..8d36168015
--- /dev/null
+++ b/src/Umbraco.Core/Models/IMediaType.cs
@@ -0,0 +1,10 @@
+namespace Umbraco.Core.Models
+{
+    /// <summary>
+    /// Defines a ContentType, which Media is based on
+    /// </summary>
+    public interface IMediaType : IContentTypeBase
+    {
+         
+    }
+}
\ No newline at end of file
diff --git a/src/Umbraco.Core/Umbraco.Core.csproj b/src/Umbraco.Core/Umbraco.Core.csproj
index 5da4fcda1e..2243896a52 100644
--- a/src/Umbraco.Core/Umbraco.Core.csproj
+++ b/src/Umbraco.Core/Umbraco.Core.csproj
@@ -99,6 +99,13 @@
     <Compile Include="Models\EntityBase\ICanBeDirty.cs" />
     <Compile Include="Models\EntityBase\IEntity.cs" />
     <Compile Include="Models\EntityBase\IValueObject.cs" />
+    <Compile Include="Models\IContent.cs" />
+    <Compile Include="Models\IContentBase.cs" />
+    <Compile Include="Models\IContentType.cs" />
+    <Compile Include="Models\IContentTypeBase.cs" />
+    <Compile Include="Models\IContentTypeComposition.cs" />
+    <Compile Include="Models\IMedia.cs" />
+    <Compile Include="Models\IMediaType.cs" />
     <Compile Include="Models\Property.cs" />
     <Compile Include="Models\PropertyCollection.cs" />
     <Compile Include="Models\PropertyGroup.cs" />