This is the cinematic open to the game Civilization IV, created in 2006-7. There are 37 separate, composited layers to this piece, 31 of which were created by Digital History Studios. Sometimes, due to lack of digital assets, some assets at hand are re-used in a way that the viewer never notices unless shown. For instance, high-resolution aerial images of Greece were not available at the time. Notice when the view comes down on the boot of Italy that in the distance where Greece should be, you'll see a flipped view of the heel of Italy's boot re-used as a texture.
For more information, see our websites: 3dhistory.com and 3dhistoryvirtualtour.com