The Battle of Yijing was a military conflict which took place in northern China from 198 to 199 in the late Eastern Han dynasty. It was fought between Gongsun Zan, a warlord known as the "White Horse General", and Yuan Shao, a scion of the esteemed Yuan clan and former leader of the coalition against Dong Zhuo.

The two warlords had been fighting for dominion over northern China for some time, but eventually Yuan Shao gained the upper hand. However, Gongsun Zan still had a large army which could cause trouble if not finished off.

Gongsun Zan, after recent military defeats in addition to a famine in his lands, decided to secure his supplies. He built a capital city called Yijing where he built many large towers on top of mounds where he and his generals lived. There were ten moats around the city and the towers had iron doors with huge grain supplies for Gongsun Zan to use to live out the civil wars of his country. In doing so, Gongsun Zan let his armies away from his fortress fight for themselves thinking they would see the only option they had was to fight hard. Instead, the soldiers killed their generals and surrendered or died easily while fighting.

In time Yuan Shao's army reached the gates of Yijing, but the city withstood several attacks from Yuan's army for years until 198. Gongsun Zan sent his son Gongsun Xu to request help from the Heishan bandits in the Taihang Mountains. Gongsun Zan's idea was to break through the siege with his cavalry and group with the Heishan bandits, then attack Ji Province (冀州) and cut off Yuan Shao's line of retreat, forcing him to abandon the siege. However, Guan Jing advised against the plan, saying that the defenders were only willing to fight to protect their families in the fortress, and could not be relied on to defend the fortress if Gongsun Zan left the city. Gongsun Zan then took Guan Jing's suggestion to withstand the siege until the time when Yuan Shao would be forced to retreat.

In the spring of 199, Gongsun Xu and Zhang Yan brought relief to Yijing with 100,000 men. Before they arrived, Gongsun Zan had sent a message to his son telling him to lay an ambush of 5,000 elite cavalry on low ground north of the city. They were then to signal Gongsun Zan to charge out of the city with his troops, planning to surround Yuan Shao's troops. However, Yuan Shao's troops caught the messenger and laid their own troops in ambush. Yuan Shao's forces then signaled Gongsun Zan, routing his unit and forcing him back into the city. Yuan Shao's troops followed up their success by digging tunnels under the city and then supporting them with beams which they later torched. The tunnel went into the center of the city and its collapse caused Gongsun Zan's towers to crumble as well. Realizing his doom, Gongsun Zan killed his sisters and wives and committed suicide by self-immolation. Yuan Shao's men climbed into the citadel and cut off Gongsun Zan's head, which was sent to Xuchang to report Yuan Shao's victory to the imperial court.

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