Though subjugated under the Mongols, the Tangut Dynasty of Xi Xia refuses to lend military support to the campaign against the Khwarzin Dynasty, instead going into open rebellion. After defeating the Khwarzins, Genghis Khan immediately takes his army back to Xi Xia and begins a string of victories over the Tanguts. After victory, he orders the execution of the Tanguts, thereby putting an end to their dynasty. Genghis ordered his generals to systematically destroy cities and garrisons as they went.