Liu Wuzhou - Campaign Against Tang

Campaign Against Tang

Liu Wuzhou, however, launched a campaign against Tang himself in late spring 619, with collateral support by Eastern Tujue forces. In summer 619, he approached Taiyuan, then defended by Emperor Gaozu's son, Li Yuanji the Prince of Qi. Li Yuanji sent the general Zhang Da (張達) against Liu, despite Zhang's reluctance, as Li Yuanji gave Zhang only a small army, and Liu defeated Zhang. Zhang, angry at Li Yuanji, instead surrendered to Liu and led Liu to capture Yuci (榆次, in modern Jinzhong, Shanxi). Soon, Liu put Taiyuan under siege. Li Yuanji initially fought him off, but soon Liu captured Shi (石州, roughly modern Lüliang, Shanxi) and Jie (介州, also part of modern Jinzhong) Prefectures, and soon, Liu's general Huang Ziying (黃子英) defeated and captured the Tang generals Jiang Baoyi (姜寶誼) and Li Zhongwen (李仲文), although Jiang and Li Zhongwen soon fled from Liu's camp.

Around the same time, Liu received additional support, in the form of the agrarian rebel leader Song Jin'gang (宋金剛), who was initially an adherent of Wei Dao'er (魏刀兒), until Wei was defeated and killed by Dou Jiande the Prince of Xia. Song was unable to resist Dou, and fled to Liu, who, believing Song to be a capable general, created him the Prince of Song and greatly honored him, even giving Song half of his possessions as a gift. Song then divorced his wife and married Liu's sister. Song then suggested to Liu that he should first capture Bing Prefecture (并州, i.e., Taiyuan) and then further attack south to try to capture more territory, to seek to unite China.

The mounting defeats concerned Tang's Emperor Gaozu, and he sent one of his senior advisors, Pei Ji, with a sizeable army to face Liu. Pei reached Jie Prefecture in the fall and placed its capital, Jiexiu (介休), under siege, with Song defending. Song soon cut off Pei's water supply, and the Tang army began to weaken in thirst, and it was defeated by Song. After the battle, Liu again approached Taiyuan, and Li Yuanji, in panic, abandoned Taiyuan and fled back to the Tang capital Chang'an. Liu then moved his capital from Mayi to Taiyuan, and soon, Song captured Jin (晉州) and Gui (澮州, together roughly modern Linfen, Shanxi) as well, and Pei was unable to resist. In shock, Tang's Emperor Gaozu considered entirely abandoning the Hedong (河東, i.e., modern Shanxi) region, but his son Li Shimin (the later Emperor Taizong) objected, offering to engage Liu. Emperor Gaozu then commissioned Li Shimin with an army and had him head toward Liu's position.