I hear this question a lot!!!
Microsoft in TFS 2010 has changed the rules in the Source Control, what happens now is when moving an Item or a Branch or using the Rename command all the history suddenly disappears.
When it happens the users are getting in to panic mode because all there history is not where they expect it to be…
So where is it and what do I need to do in order to see my history?
In order to see what happens lets create a similar situation where my history “disappears”:
I will take the branch Iteration 2 from Development folder to Release folder.

Checking the history of the branch shows me a big list of changesets.


Moving the branch…

Now lets check the history, you can see that I get only one result, the Move action.


So what happened? basiclly the history belongs to the “old” location so it staied there.
When moving an object from one location to another the system deletes the old location and creates the new one, what we get is that History is under the deleted location.
Lets check it now…

You can see that all the history is there…


You can use my post: “Show Deleted Items In TFS Source Control” to make the deleted files visible.
Have Fun!!!