Seriously cool map

I'm a sucker for maps. Any kind of maps. I'll sit and look through an atlas for hours as if it were the Sports Illustrated Swimsuit issue.

So my Lovely and Brilliant Wife sent me this interactive historical map of Europe. You can go century by century from the year 1 to 2000, and see what peoples occupied which regions and which long-forgotten kingdom, empire or tinpot duchy was where.

I'm in grave danger of sitting and playing with this thing and neglecting my work.