diff --git a/src/Umbraco.Core/Events/NewEventArgs.cs b/src/Umbraco.Core/Events/NewEventArgs.cs
index d74cb24b5c..135caa78f6 100644
--- a/src/Umbraco.Core/Events/NewEventArgs.cs
+++ b/src/Umbraco.Core/Events/NewEventArgs.cs
@@ -1,15 +1,27 @@
 namespace Umbraco.Core.Events
 {
-	public class NewEventArgs : System.ComponentModel.CancelEventArgs
+	public class NewEventArgs<TEntity> : CancellableObjectEventArgs<TEntity>
 	{
+		public NewEventArgs(TEntity entity, bool canCancel, string @alias, int parentId) : base(entity, canCancel)
+		{
+			Alias = alias;
+			ParentId = parentId;
+		}
+
+		public NewEventArgs(TEntity entity, string @alias, int parentId) : base(entity)
+		{
+			Alias = alias;
+			ParentId = parentId;
+		}
+
 		/// <summary>
 		/// Gets or Sets the Alias.
 		/// </summary>
-		public string Alias { get; set; }
+		public string Alias { get; private set; }
 
 		/// <summary>
 		/// Gets or Sets the Id of the parent.
 		/// </summary>
-		public int ParentId { get; set; }
+		public int ParentId { get; private set; }
 	}
 }
\ No newline at end of file
diff --git a/src/Umbraco.Core/Models/ContentBase.cs b/src/Umbraco.Core/Models/ContentBase.cs
index 9729fa8edd..fd4692cb33 100644
--- a/src/Umbraco.Core/Models/ContentBase.cs
+++ b/src/Umbraco.Core/Models/ContentBase.cs
@@ -27,7 +27,7 @@ namespace Umbraco.Core.Models
 
         protected ContentBase(int parentId, IContentTypeComposition contentType, PropertyCollection properties)
         {
-            //Mandate.ParameterCondition(parentId != 0, "parentId");
+            Mandate.ParameterCondition(parentId != 0, "parentId");
             Mandate.ParameterNotNull(contentType, "contentType");
             Mandate.ParameterNotNull(properties, "properties");
 
diff --git a/src/Umbraco.Core/Models/ContentTypeBase.cs b/src/Umbraco.Core/Models/ContentTypeBase.cs
index 22a1c65ad9..d44b132832 100644
--- a/src/Umbraco.Core/Models/ContentTypeBase.cs
+++ b/src/Umbraco.Core/Models/ContentTypeBase.cs
@@ -33,6 +33,8 @@ namespace Umbraco.Core.Models
 
         protected ContentTypeBase(int parentId)
         {
+			Mandate.ParameterCondition(parentId != 0, "parentId");
+
             _parentId = new Lazy<int>(() => parentId);
             _allowedContentTypes = new List<ContentTypeSort>();
             _propertyGroups = new PropertyGroupCollection();
@@ -40,6 +42,8 @@ namespace Umbraco.Core.Models
 
 		protected ContentTypeBase(IContentTypeBase parent)
 		{
+			Mandate.ParameterNotNull(parent, "parent");
+
 			_parentId = new Lazy<int>(() => parent.Id);
 			_allowedContentTypes = new List<ContentTypeSort>();
 			_propertyGroups = new PropertyGroupCollection();
diff --git a/src/Umbraco.Core/Services/ContentService.cs b/src/Umbraco.Core/Services/ContentService.cs
index 7143c6ae8b..9a3e3f6b92 100644
--- a/src/Umbraco.Core/Services/ContentService.cs
+++ b/src/Umbraco.Core/Services/ContentService.cs
@@ -84,23 +84,17 @@ namespace Umbraco.Core.Services
 				if (contentType == null)
 					throw new Exception(string.Format("ContentType matching the passed in Alias: '{0}' was null", contentTypeAlias));
 
-				IContent content = null;
+				var content = new Content(parentId, contentType);
 
-				var e = new NewEventArgs { Alias = contentTypeAlias, ParentId = parentId };
-				if (Creating != null)
-					Creating(content, e);
+				if (Creating.IsRaisedEventCancelled(new NewEventArgs<IContent>(content, contentTypeAlias, parentId), this)) 
+					return content;
+				
+				SetUser(content, userId);
+				SetWriter(content, userId);
 
-				if (!e.Cancel)
-				{
-					content = new Content(parentId, contentType);
-					SetUser(content, userId);
-					SetWriter(content, userId);
+				Created.RaiseEvent(new NewEventArgs<IContent>(content, false, contentTypeAlias, parentId), this);
 
-					if (Created != null)
-						Created(content, e);
-
-					Audit.Add(AuditTypes.New, "", content.CreatorId, content.Id);
-				}
+				Audit.Add(AuditTypes.New, "", content.CreatorId, content.Id);
 
 				return content;	
 			}
@@ -1310,12 +1304,12 @@ namespace Umbraco.Core.Services
 		/// <summary>
 		/// Occurs before Create
 		/// </summary>
-		public static event EventHandler<NewEventArgs> Creating;
+		public static event TypedEventHandler<IContentService, NewEventArgs<IContent>> Creating;
 
 		/// <summary>
 		/// Occurs after Create
 		/// </summary>
-		public static event EventHandler<NewEventArgs> Created;
+		public static event TypedEventHandler<IContentService, NewEventArgs<IContent>> Created;
 
 		/// <summary>
 		/// Occurs before Copy
diff --git a/src/Umbraco.Core/Services/MediaService.cs b/src/Umbraco.Core/Services/MediaService.cs
index 3f558de1fc..9da0192bf8 100644
--- a/src/Umbraco.Core/Services/MediaService.cs
+++ b/src/Umbraco.Core/Services/MediaService.cs
@@ -66,21 +66,14 @@ namespace Umbraco.Core.Services
 
 				var media = new Models.Media(parentId, mediaType);
 
-				var e = new NewEventArgs { Alias = mediaTypeAlias, ParentId = parentId };
+				if (Creating.IsRaisedEventCancelled(new NewEventArgs<IMedia>(media, mediaTypeAlias, parentId), this)) 
+					return media;
 				
-				if (Creating != null)
-					Creating(media, e);
+				SetUser(media, userId);
 
-				if (!e.Cancel)
-				{
-					
-					SetUser(media, userId);
+				Created.RaiseEvent(new NewEventArgs<IMedia>(media, false, mediaTypeAlias, parentId), this);
 
-					if (Created != null)
-						Created(media, e);
-
-					Audit.Add(AuditTypes.New, "", media.CreatorId, media.Id);
-				}
+				Audit.Add(AuditTypes.New, "", media.CreatorId, media.Id);
 
 				return media;	
 			}
@@ -457,12 +450,12 @@ namespace Umbraco.Core.Services
 		/// <summary>
 		/// Occurs before Create
 		/// </summary>
-		public static event EventHandler<NewEventArgs> Creating;
+		public static event TypedEventHandler<IMediaService, NewEventArgs<IMedia>> Creating;
 
 		/// <summary>
 		/// Occurs after Create
 		/// </summary>
-		public static event EventHandler<NewEventArgs> Created;
+		public static event TypedEventHandler<IMediaService, NewEventArgs<IMedia>> Created;
 
 		/// <summary>
 		/// Occurs before Content is moved to Recycle Bin