Within half a century of Genghis Khan's death, they will have conquered not just northern Asia. When they capture Baghdad, many historians consider this the end of the Islamic Golden Age. As much pressure as the Western Europeans were putting on the Turks during their crusades, it was actually the Mongol threat that was much more significant. Before fragmenting, it is the largest contiguous empire in world history. I use the word contiguous because the British Empire actually covers more land, as we'll see, a few hundred years later. But the Mongolian Empire, all of the land was connected. It was contiguous.