Genghis Khan invades Khwarazmia

After the Khwarazmian governor of Otrar kills a Mongol caravan in 1218, Genghis Khan invades in 1219-1221. Bukhara, Samarkand and Gurganj fall; Shah Muhammad II flees toward the Caspian and dies there around December 1220. Traditional death tolls are held exaggerated.