The Jurchens (Nüzhen, a Tungus people) inhabited northeast China, including the Changbai Mountains and the drainage areas of the Songhua and Heilong rivers. In 1115, led by Wanyan Aguda, they established the Jin (Kin) Dynasty and based their capital in Huining (now Acheng in Heilongjiang). In the decade that followed, the Jin Dynasty continued to expand its territory, moving its political center south to the Liao Dynasty's Nanjing (South Capital, now Beijing), renaming it Zhongdu ("Middle Capital"). In 1126, Jin forces launched a southern expedition to annihilate the Northern Song Dynasty. By then, Jin territory bordered Western Xia to the west and was separated from the Southern Song by the Qinling Mountains and the Huaihe River. In 1234, the Jin Dynasty, which lasted 120 years, collapsed due to attacks from both Mongols and the Southern Song.