Wanyan Aguda proclaims the Jin empire

The Jurchens, a Tungusic people of the forests and river valleys of Manchuria, were subjects of the Khitan Liao, which exacted tribute from them, including gyrfalcons, and whose envoys abused their villages. In the 11th century the chiefs of the Wanyan clan gradually united the Jurchen tribes. In 1112, at a feast during Emperor Tianzuo's fishing expedition on the Songhua River, Aguda alone refused to dance for the Liao ruler; in 1113 he succeeded his brother as chief. In the autumn of 1114 he assembled 2,500 warriors on the Lailiu (Lalin) River, took the Liao frontier town of Ningjiang and routed a Liao army at Chuhedian; the History of Jin recalls the Liao saying that a Jurchen army of ten thousand would be invincible — and now, it says, it had reached that number. Aguda organised his people into units of 300 households (mouke), ten of which formed a mengan.

His followers urged him to take the imperial title, and on the first day of the first month of 1115 — 28 January — Aguda was enthroned. According to the History of Jin he explained the dynastic name: the Liao had named itself after fine iron for its hardness, but iron in the end decays, whereas gold neither changes nor decays — and white, the colour of gold, was the colour the Wanyan prized. He also took the Chinese name Min and the era name Shouguo; a Balhae adviser, Yang Pu, who had passed the Liao examinations, is credited with urging him to aspire to an empire on the Chinese model. In the autumn the Jin took Huanglong, and at the turn of 1115–1116, by the History of Jin's count, 20,000 Jurchen horsemen routed Emperor Tianzuo's army, reputed to number 700,000, at Hubudagang. The History of Liao, however, dates Aguda's enthronement and the name Jin to 1117, and the historian Liu Pujiang has argued that the Jin court later reshaped the story of its founding: the state may first have been simply a Jurchen state, founded in 1117 or 1118, that took the name Great Jin only in 1122.

From 1117 the Song, hoping to recover the Sixteen Prefectures lost to the Liao, negotiated an alliance with the Jin — the ‘Alliance Conducted at Sea’. The Jin took the Liao capitals one after another — the Eastern Capital in 1116, the Supreme Capital in 1120, the Central and Western capitals in 1122 and Yanjing, the Southern Capital, in January 1123. Aguda died on 19 September 1123; his brother and successor Wuqimai (Emperor Taizong) captured the fugitive Liao emperor in 1125, while the Liao prince Yelü Dashi led a band of Khitans west to Central Asia. The Jin then turned on its Song ally, and it ruled northern China until the Mongols destroyed it in 1234.