新五代史
During the reigns of Later Tang's first two emperors, Li Cunxu and Li Siyuan, Zhang Yanze served as a cavalry officer. (It is possible, although not clearly stated in historical accounts, that he might have already been serving under Li Cunxu prior to the founding of Later Tang, when Li Cunxu was the prince of Later Tang's predecessor state Jin.) Due to his accomplishments, he was given terms as prefects for several prefectures. (During this time, his family might have entered into a political alliance by marriage with that of Li Siyuan's son-in-law Shi Jingtang, as suggested by the "New History of the Five Dynasties"; the "Zizhi Tongjian" suggested, instead, that the political alliance by marriage was with the family of another general, Yang Guangyuan.)