Kyrgyz people
In 840, the Kyrgyz allied with the Tang dynasty to defeat the Uyghur Khaganate (Mongolia). The Kyrgyz qaghan (king) killed the Uyghur qaghan and rescued Princess Taihe. They moved to Jeti-su and spread south to the Tian Shan mountains and Xinjiang. The Kyrgyz then lived peacefully around Central Asia and Xinjiang, as vassals to the Tang.