the military governor of Datong Circuit (大同, headquartered in modern Datong, Shanxi). At that time, it was frequent that the tribal forces of the Khitan Empire would send herds into Later Tang territory to graze. Zhang put sufficient garrisons on the border such that the Khitan did not dare to enter Datong territory, and it was said that the people in the border regions relied on him for protection. After Li Siyuan's reign By 935, Li Siyuan's adoptive son Li Congke had become emperor. That year, there was an incident in which his brother-in-law (Li Siyuan's son-in-law) Shi Jingtang, then the military governor of Hedong and who also carried the title of the commander of the armies in the north (i.e., on the Khitan border), was hailed by his soldiers with, "May you live 10,000 years!" (traditionally a hail for the emperor only) while he led his troops at Xin Prefecture (忻州, in modern Xinzhou) in defending against a potential Khitan attack. While Shi executed 36 soldiers who led the hail, it nevertheless caused Li Congke, who had already been previously suspicious of Shi's intentions, to be more concerned. He thus commissioned Zhang Jingda, who was then serving as the military governor of Wuning Circuit (武寧, headquartered in modern Xuzhou, Jiangsu), as the deputy commander of the armies in the north, stationed at Dai, to divide Shi's army. (Either at the same time or thereafter, his own military governorship was transferred from Wuning to Jianxiong Circuit (建雄, headquartered in modern Linfen, Shanxi). In spring 936, in order to test Li Congke's intentions toward him, Shi requested to be transferred. Believing that Shi would rebel if he transferred Shi but that he could defeat the rebellion, Li Congke issued an edict transferring Shi to Tianping Circuit (天平, headquartered in modern Tai'an, Shandong) and a close associate, Song Shenqian () the military governor of Heyang Circuit (河陽, headquartered in modern Jiaozuo, Henan) to Hedong. He also ordered Zhang to go to Hedong to "escort" Shi from Hedong to Tianping, to put pressure on Shi. Shi thereafter rebelled, issuing a declaration claiming that as Li Congke was an adoptive son, he should not be emperor, and that he should pass the throne to a younger brother, Li Congyi the Prince of Xu (Li Siyuan's youngest biological son). Li Congke, in response, put Zhang in command of an army to attack Hedong, with Yang