 In <unk> , the chieftain Wanyan Aguda ( <unk> – 1123 ) united the disparate Jurchen tribes and led a revolt against the Liao . In 1115 he named himself emperor of the Jin " golden " dynasty ( 1115 – 1234 ) . <unk> by a Liao <unk> of the success of the Jurchen uprising , the Song emperor Huizong ( r . 1100 – 1127 ) and his highest military commander the <unk> Tong Guan saw the Liao weakness as an opportunity to recover the Sixteen Prefectures , a line of fortified cities and passes that the Liao had annexed from the <unk> Turk Later Jin in 938 , and that the Song had repeatedly but unsuccessfully tried to <unk> . The Song thus sought an alliance with the Jin against their common enemy the Liao . 
