Genghis escapes the heat in August 122 by residing in the Qilian Mountains while his troops approach Wuwei, the second-largest city of the Western Xia empire.

As no relief comes from the capital, Wuwei decides to surrender and avoid certain destruction.

At this point, Emperor Xianzong dies, leaving Mozhu to deal with a collapsing state as the Mongols encroach on the capital.

In autumn, Genghis rejoins his troops, takes Liangchow, crosses the Helan Shan desert, and …

…in November lays siege to Lingwu, a mere thirty kilometers from Yinchuan.

Here, in the Battle of Yellow River, Western Xia leads a counterattack with an estimated force of over three hundred thousand troops, engaging Mongol forces along the banks of the frozen river and canal systems.

The Mongols destroy the Western Xia troops, supposedly counting three hundred thousand bodies of Western Xia soldiers after the battle.

Genghis, upon reaching Yinchuan in 1227 and laying siege to the city, prepares to invade the Jin dynasty in order to neutralize any threat of them sending relief troops to Western Xia as well as setting the stage for a final conquest of the Jin empire.

Genghis sends a force under his son Ogedai and commander Chagaan toward the southern border, and they push into Jin territories along the Wei River and south Shaanxi, even sending some troops over the Qin Mountains to threaten Kaifeng, the Jin capital.

Genghis himself rejoins with Subutai and heads southwest to slice across an approximately one hundred and fifty kilometer-wide territory, mainly in present-day Ningxia and Gansu.

Subutai crosses the northern parts of the Liupan mountain range, zigzagging from town to town throughout February and March, and conquers the Tao River valley and Lanzhou region.

Genghis meanwhile travels due south, following the Qing Shui river.

Back in Western Xia, Yinchuan lies besieged for about six months, and Genghis, himself busy directing a siege of Longde, sends Chagaan to negotiate terms.

Chagaan reports that the emperor has agreed to capitulate, but wants a month to prepare suitable gifts.

Genghis assents, although he secretly plans to kill the emperor.

During the peace negotiations, Genghis continues his military operations around the Liupan mountains near Guyuan, rejectes an offer of peace from the Jin, and prepares to invade them near their border with the Song.

Genghis, however, dies in August 1227 of uncertain causes; his death is kept a secret in order not to jeopardize the ongoing campaign.

Emperor Mozhu in September of 1227 surrenders to the Mongols, now led by Genghis Khan’s son Tolui, and, in fear that the Western Xia will rebel, is promptly executed along his entire family.

His death marks the end of the Western Xia dynasty.

The Mongols now mercilessly pillage Yinchuan, put to the sword the intellectuals and most of the citizenry, plunder the imperial tombs west of the city, and complete the effective annihilation of the Western Xia state.

The Mongols transport their dead leader back to Mongolia, killing everyone that crosses their path, and bury their leader in a secret location.