Antecedents: Battle of Dingtao; Consequences: Liu Bangjun came to Ba, and Xiang Yu came to Xianyang.
Battle of Dingtao: Xiang Liang dies, and the anti-Qin alliance is on the verge of collapse.
From leap September 208 BC to July 207 BC, Xiang Yu led a 60,000-strong Chu army and fought a thrilling decisive battle with the main force of 400,000 Qin troops led by the Qin general Zhang Han Wang and Li Li, known as the Battle of Julu.
Emperor Chuyi judged the time and sized up the situation, and the army was divided into two ways to defeat the Qin army. After defeating Xiang Liang in the Battle of Dingtao, Zhang Wei made a fatal mistake: he believed that the main force of the Chu state had become the end of the crossbow, and there was nothing to worry about. Therefore, he hastily decided to jump over the Yellow River and attack the state of Zhao.
On the side of the State of Zhao, Zhao Xie, the King of Zhao, and Zhang Er, the minister of state, both fled into the capital Julu. As one of the generals of the State of Zhao, Chen Yu led tens of thousands of soldiers to station north of Julu, which was the so-called "Hebei Army". The situation in the Zhao Kingdom was so critical that in desperation, he had to frequently ask the Chu army for help.
Zhang Wei seems to have become an iron wall that no one can stop. He ordered Wang Li and Watama to surround Julu, while his own army was stationed south of Julu and built walled roads on both sides to deliver food and grass to them.
On the Chu side, Xiang Yu and Liu Bang, the two commanders of the Chu army, reached a consensus that the siege of the Zhao state must be lifted immediately. Liu Bang took over the Chu army after Xiang Liang's death, while Xiang Yu had just emerged from the defeat of the anti-Qin alliance. Both of their commanders of the Chu army understood that in order to break the encirclement of the Qin army, a decisive battle must be waged.
At this time, the state of Zhao was on the verge of collapse. They sent a distress signal to the Chu army, hoping that they could rush to Julu as soon as possible and rescue the Zhao state. And the Chu army also realized the seriousness of the problem, so they immediately began to prepare for action.