Diablo III has been in development for a long, long time - which is to be expected when it comes to Blizzard's games. In fact, it has been worked on for at least six years and a lot has happened since then.
The game was originally in development at Blizzard North, but when the studio was closed and the project was transferred to California everything that had been done up to that point was scrapped. Now Kotaku has dug up some screenshots from it (which we've included below), which give us an insight into what the game could have looked like if Blizzard North had finished it.
The pictures are from 2005, and show a quite different Diablo III from what we now have - for example, it was set in Heaven.