 Meanwhile, though, Tang forces were still not able to expel Huang from the Chang'an region.Yang Fuguang, the eunuch monitor of the army in the Hezhong (河中, headquartered in modern Yuncheng, Shanxi) region, suggested to Wang Chongrong the military governor of Hezhong that another attempt be made to invite Li Keyong to join the operations against Huang.At Yang's suggestion, the overall commander of the operations, the former chancellor Wang Duo wrote both Li Keyong and Zheng, summoning Li Keyong while requesting that Zheng allow Li Keyong's Shatuo troops passage through Hedong.