Mongol Conquest of Western Xia
Also called: Fall of Western Xia
Genghis Khan attacked the Tangut state of Western Xia several times, forcing its submission and finally destroying it in 1227. He died during this last campaign.

Thebrainchamber1 · CC BY-SA 4.0 · Source
Western Xia was the first settled state the Mongols attacked. In 1209 Genghis Khan besieged its capital Zhongxing and made Xia a vassal, a springboard against the Jin. When Xia refused to send troops for the war on Khwarazm, Genghis returned from the west and invaded again in 1226. Zhongxing surrendered in 1227, and Genghis died on campaign that summer. Following his last orders the Mongols massacred the surrendered Tanguts, and the history and script of Western Xia were long forgotten.