The Liao Dynasty, also known as the Great Liao 大遼 or the Khitan Empire 契丹国, was an empire in East Asia that ruled from 907 to 1125 over present-day Mongolia and portions of the Russian Far East, Northern Korea, and Northern China. The empire was founded by Abaoji 阿保机, Khagan of the Khitan people, around the time of the collapse of Tang China and was the first state to control all of Manchuria.