In 840 a revolt led by the Yenisei Kyrgyz brought down the Uyghur Khaganate, and brought the Yenisei Kyrgyz to a dominating position in the former Second Turkic Khaganate. With the rise to power, the center of the Kyrgyz Khaganate moved to Jeti-su, and brought about a spread south of the Kyrgyz people, to reach Tian Shan mountains and Xinjiang, bringing them into contact with the existing peoples of western China, especially Tibet.