The Tang Dynasty: Qin Wang’s Eastern Campaign

In the third year of the Wude era of the Tang dynasty, Prince of Qin Li Shimin led an army east to attack Wang Shichong, who had established himself as a warlord in Luoyang. The Tang forces won battle after battle, eventually laying siege to the isolated city. Dou Jiande of Hebei personally led a large army to relieve it, but Li Shimin decisively split his forces to hold Hulao Pass, ambushed the enemy with a smaller force, and captured Dou Jiande alive. Seeing that all was lost, Wang Shichong opened the city gates and surrendered. This battle put an end to two major separatist powers at once and swept across the Central Plains, laying a vital foundation for the Tang dynasty's unification of the country.