1 , ▁Yan ▁X ish an ▁divided ▁his ▁forces ▁into ▁three ▁Route ▁Arm ies , ▁a ▁Caval ry ▁Army ▁and ▁a ▁Reserve ▁Army , ▁with ▁tro op ▁dispos itions ▁to ▁be ▁completed ▁as ▁soon ▁as ▁Tang ▁En bo ' s ▁forces ▁arrived . ▁However , ▁the ▁Japanese ▁struck ▁first ▁on ▁November ▁ 1 5 , ▁ 1 9 3 6 . ▁ ▁S ui y uan ▁Camp aign ▁▁ ▁The ▁invasion ▁of ▁S ui y uan ▁began ▁on ▁November ▁ 1 4 , ▁ 1 9 3 6 , ▁when ▁a ▁coal ition ▁of ▁the ▁Inner ▁Mong ol ian ▁Army ' s ▁ 7 th ▁and ▁ 8 th ▁Caval ry ▁Div isions , ▁Wang ▁Y ing ' s ▁Grand ▁Han ▁R igh te ous ▁Army , ▁and ▁Mong ol ▁mer cen aries ▁from ▁Je hol , ▁Ch ah ar ▁and ▁other ▁areas , ▁supported ▁by ▁ 3 0 ▁Japanese ▁advis ors , ▁attacked ▁the ▁Chinese ▁g arrison ▁at ▁Hong ort . ▁ ▁After ▁several ▁days ▁of ▁fighting ▁the ▁attack ers ▁failed ▁to ▁capture ▁the ▁town . ▁On ▁November ▁ 1 7 ▁a ▁Chinese ▁counter att ack ▁surprised ▁the ▁inv aders ▁and ▁led ▁to ▁a ▁dis organ ized ▁retre at . ▁T aking ▁advantage ▁of ▁the ▁Mong ol ian ▁dis order ▁General ▁Fu ▁Zu oy i ▁made ▁a ▁fl ank ing ▁movement ▁to ▁the ▁west ▁of ▁the ▁Mong ol ian ▁headquarters ▁at ▁B ail ing m iao ▁and ▁attacked , ▁capt uring ▁it ▁and ▁routing ▁the ▁Mong ol ian ▁forces . ▁ ▁Wang