Wang Zai (), né Wang Yanzai (), was a general of the Chinese Tang Dynasty, most well known for his participation in Emperor Wuzong's campaign against the warlord Liu Zhen, who ruled Zhaoyi Circuit (昭義, headquartered in modern Changzhi, Shanxi).
Background
It is not known when Wang Yanzai was born, but it is known that he was probably the second of nine sons of his father Wang Zhixing, who was a long-time military governor (Jiedushi) of Wuning Circuit (武寧, headquartered in modern Xuzhou, Jiangsu). He was considered the most talented among his brothers. At an unknown point in his life, the character "Yan" was removed from his name, and he became known just as Wang Zai. One of his sons, Wang Yanshi (), was so loved by his father Wang Zhixing that Wang Zhixing adopted Wang Yanshi as his own son, so legally, Wang Yanshi became a brother to him.
Early career
Wang Zai was said to be resolute in his youth, and he became an officer in the Shence Armies, then under the control of the powerful eunuchs. He was said to have participated in suppressing the plot by Emperor Wenzong and his associates Li Xun and Zheng Zhu to slaughter the eunuchs in 835 — known as the Ganlu Incident — while serving in the Shence Armies. Thereafter, he served as the prefect of Guang Prefecture (光州, in modern Xinyang, Henan). Subsequently, at the suggestion of his superior, the former chancellor Duan Wenchang the military governor of Huainan Circuit (淮南, headquartered in modern Yangzhou, Jiangsu), Wang was moved to be the prefect of Yan Prefecture (鹽州, in modern Yulin, Shaanxi). It was said that he was strict at Yan Prefecture and the people did not appreciate him. He was later promoted to be the military governor of Binning Circuit (邠寧, headquartered in modern Xianyang, Shaanxi). After the campaigns against the remnants of the Huigu Khanate early in the reign of Emperor Wenzong's brother and successor Emperor Wuzong, in 843, Wang was moved to be the military governor of Zhongwu Circuit (忠武, headquartered in modern Xuchang, Henan).
Campaign against Zhaoyi
Soon after Wang Zai's commission as military governor of Zhongwu, Emperor Wuzong declared a general campaign against Liu Zhen, who had seized control of Zhaoyi Circuit after the death of his adoptive father (and biological uncle) Liu Congjian, who was previously military governor, without imperial sanction. Initially, Zhongwu was not one of the circuits mobilized against Zhaoyi. However, He Hongjing the military governor of Weibo Circuit (魏博, headquartered in modern Handan, Hebei) — one of the circuits that Emperor Wuzong did mobilize — who had been governing Weibo in de facto independence from the imperial government, had been trying to intercede on Liu Zhen's behalf, and had not launched his own troops against Zhaoyi. In order to pressure He Hongjing, Emperor Wuzong ordered Wang Zai to mobilize his troops and cut through Weibo to attack Zhaoyi's Ci Prefecture (磁州, in modern Handan). When He Hongjing heard of Wang's orders, he became apprehensive that if Zhongwu forces entered Weibo that his soldiers could rebel against him; he thus launched his troops in a hurry to attack Ci Prefecture.
After He Hongjing launched his troops, with the objective of pressuring He Hongjing having been accomplished, Emperor Wuzong, at the advice of the lead chancellor Li Deyu, diverted Wang Zai to Heyang Circuit (河陽, headquartered in modern Jiaozuo, Henan) instead, as Heyang troops had recently been dealt a serious defeat by Zhaoyi forces under the command of the officer Xue Maoqing (), and its defense had been further hampered by the illness that its military governor Wang Maoyuan () was suffering. When Wang Maoyuan subsequently died, Emperor Wuzong had Wang Zai take over the command of the Heyang troops, then at Wanshan (萬善, in modern Jiaozuo, Henan), as well, although he gave the command of the circuit itself to Jing Xin (), rather than giving Wang Zai the command of Heyang as well.