Mongol invasion of the Khwarazmian Empire

Khwarazmian Empire (1190–1220), on the eve of the Mongol conquests

01After the fall of Nishapur in 1221, Genghis Khan's daughter-in-law ordered every living thing killed — including dogs and cats — to avenge her husband.
02The Mongols reportedly stacked 1.7 million skulls into pyramids outside Nishapur; modern mass graves continue to be discovered in the region.
03The Khwarezmian Shah Muhammad II fled across his own empire until he died alone of pleurisy on a Caspian island, abandoned by all his followers.

Artist's conception of a powerful magnetar in a star cluster

Between 1219 and 1221, Genghis Khan reduced the Khwarezmian Empire — 5 million people — to mass graves and depopulated cities. The skulls outside Nishapur were stacked into pyramids. Archaeologists still find the layers.