Ambaghai

Ambaghai Khan was a khan of Khamag Mongol in 1149–1156, one of the great grandsons of Khaidu Khan and the cousin and predecessor of Hotula Khan. During his rule, he was captured by the Tatars under the commands of the Chinese jurchen (tungusic people) Jin dynasty in response to the Mongols' growing power.

In 1211 Genghis Khan began the Mongol–Jin War, causing the eventual fall of the Jin dynasty, in sworn revenge for Ambaghai's kidnapping and execution.

Ambaghai was a relative of Yesugei and Genghis Khan.

...
Wikipedia