Wanyan Aguda, whose Chinese name is Wanyanmin, is the second son of Gailibo, the leader of the Jurchen Wanyan tribe. The Jurchens lived in Baishan and Heishui for a long time and were ruled by Liao Dynasty for a long time. The Liao Dynasty demanded Haidongqing and Beizhu every year, and the "Silver Angel" sent by the Liao Dynasty even bullied various ministries. Aguda was famous for his bravery and good shooting when he was young. After the death of his brother Wu Yashu in 1113, he succeeded Dubo Jilie and commanded the Jurchen tribes.
In 1114, he swore an oath to rebel against the Liao Dynasty at Lailiushui, and even conquered Jiangzhou and Chuhedian in Ning. In the first month of the following year, he proclaimed himself emperor, named his country Dajin, and conquered the country in Jianyuan, with Huining as his capital. In the same year, Emperor Tianzuo's personal army was defeated at Hubu Dagang. After that, he successively captured Liaodong, Shangjing, Zhongjing, and Xijing, and entered into a "maritime alliance" with Northern Song to attack from both sides. In 1122, the Song army failed to attack Yan, and the Jin army entered Yanjing from Juyongguan. Liao dynasty captured all the five capitals.
In the process of founding the country, he reorganized Meng'an Muke, established Bojilie to assist the government, and ordered Wanyan Xiyin to create the Jurchen script, so that the tribal alliance quickly grew into a country. In 1123, he handed over Yanjing and six states to Northern Song as agreed, but took away Yanjing's population and wealth in advance. In August of the same year, he died of illness on the way back to Beijing. He was fifty-six years old and was succeeded by his younger brother Wu Qimai.
Aguda raised an army with thousands of people and captured almost all the territory of Liao Dynasty in less than ten years. His military ability and decisiveness were quite outstanding among the founding monarchs of the past dynasties. He integrated the Jurchen tribes, created writing, and established the Men'an Mooke and Bojilie systems, allowing the tribal alliance to quickly grow into a country. However, the Jin and Song Dynasties in the Maritime Alliance each had their own plans. After the destruction of the Liao Dynasty, the conflicts between the two sides intensified immediately, paving the way for the N&S War that would last more than a hundred years.