The Mongols and their conquest of southwest Asia

The Mongol Empire was founded in the late twelfth and early thirteenth centuries by Temüchin, later known as Chinggis Khan (died AD 1227), who united the Mongolian and Turkish-speaking tribes of the eastern Eurasian steppe and forged an empire which within the span of two generations was to stretch across Asia. Having put the Inner Asian steppe under his sway and obtained the submission of the Tanguts of the Hsi-Hsia state in northwest China, Tibet and Chinese Turkestan (1209), Chinggis Khan commenced his campaign against the north Chinese state of the Chin in 1211. While this conquest was not yet completed by the end of the decade, it was well enough along for Chinggis Khan to turn his attention to the west. One of his generals had already defeated the ruler of the Qara-Khitai in western Turkestan, obliterated this state and integrated its territory into the Mongol Empire.

In 1219, Chinggis Khan launched a massive offensive against the Khwārazm-shāh, who controlled most of the eastern Islamic world. The campaign had been sparked off by the Khwārazm-shāh's truculent attitude towards the Mongols and by his governor's murder of several hundred Muslim merchants under Mongol protection.