[1] During the Mongol conquest of Western Xia and the Jin dynasty (1207 - 1215 CE), while Genghis Khan's army was on campaign, many previously conquered Siberian tribes under the leadership of Botohui-Tarhun stopped sending the Mongols tributes of furs and women.
The Mongols send an envoy to investigate why the tributes had stopped and to demand 30 maidens from the tribes as wives.
[4] In 1219 (Year of the Hare), Genghis Khan sent a general with a detachment to investigate.
Botohui-Tarhun's forces ambushed the detachment in the forest and killed the general.
According to The Secret History, the Mongol attack was so fast that it appeared they had entered "through the top of the smoke-holes of [the Siberian tribes'] tents"[4] Upon victory, the Mongols imprisoned the members of the tribe.