 The western army , led by Wanyan Zonghan , departed from Datong and headed towards Taiyuan through the mountains of Shanxi , on its way to the Song western capital Luoyang . The Song forces were not expecting an invasion and were caught off guard . The Chinese general Tong Guan was informed of the military expedition by an envoy he had sent to the Jin to obtain the cession of two prefectures . The returning envoy reported that the Jurchens were willing to forgo an invasion if the Song ceded control of Hebei and Shanxi to the Jin . Tong Guan retreated from Taiyuan and left command of his troops to Wang Bing . Jin armies besieged the city in mid January 1126 . Under Wang Bing 's command , Taiyuan held on long enough to stop the Jurchen troops from advancing to Luoyang . 
 The western army , led by Wanyan Zonghan , departed from Datong and headed towards Taiyuan through the mountains of Shanxi , on its way to the Song western capital Luoyang . The Song forces <a href='uninflect' title='1'><mark>were</mark></a> not expecting <a href='None' title='2'><mark>an</mark></a><a href='negative_concord' title='3'><mark>invasion</mark></a> and <a href='uninflect' title='4'><mark>were</mark></a> caught off guard . The Chinese general Tong Guan was informed of the military expedition by an envoy he <a href='been_done' title='5'><mark>had</mark></a> sent to the Jin to obtain the cession of two prefectures . The returning envoy reported that the Jurchens <a href='uninflect' title='6'><mark>were</mark></a> willing to forgo an invasion if the Song ceded control of Hebei and Shanxi to the Jin . Tong Guan retreated from Taiyuan and left command of his troops to Wang Bing . Jin armies besieged the city in mid January 1126 . Under Wang Bing <a href='null_genetive' title='7'><mark>'s</mark></a>command , Taiyuan held on long enough to stop the Jurchen troops from advancing to Luoyang . 
The western army , led by Wanyan Zonghan , departed from Datong and headed towards Taiyuan through da mountains of Shanxi , on its way to tdaSong western capital Luoyang . The Song forces was not expecting no invasion and was caught offf guard . Thdahinese general Tong Guan was informed of the military expedition by an envoy he done sent to the Jin to obtain thedassion of two prefectures . The returning envoy reported that the Jurchens was willin to forgo an invasion if the Song ceded control of Hebei and Shanxi to the Jin . Tong Guan retreated from Taiyuan and left command of his troops to Wang Bing . Jin armies besieged the day in mid January 1126 . Under Wang Bing  command , Taiyuan held on long enough to stop the Jurchen troops from advancing to Luoyang .