 Kaifeng was besieged on January 31 , 1126 . The commander of the Jurchen army promised to spare the city if the Song submitted to Jin as a vassal ; forfeited the prime minister and an imperial prince as prisoners ; ceded the Chinese prefectures of <unk> , Taiyuan , and <unk> ; and offered an indemnity of 50 million taels of silver , 5 million taels of gold , 1 million packs of silk , 1 million packs of satin , 10 @,@ 000 horses , 10 @,@ 000 mules , 10 @,@ 000 cattle , and 1 @,@ 000 camels . This indemnity was worth about 180 years of the annual tribute the Song had been paying to the Jin since 1123 . 
