Second rout of the Jiangnan Daying

The Second rout of the Jiangnan Army Group or the Jiangnan DaYing; (1857–1860) was the deployment of the Qing government's Green Standard Army to crush the Taiping Rebellion. The Green Standard Army twice attempted to besiege the Taiping rebels' capital Nanjing but was defeated both times by the rebel force's military strategies and tactics.

Jiangnan
General Li Xiucheng of the rebel forces encircled the region of Jiangnan, taking over Hangzhou in the process, leading to its mayor committing suicide.

Li's daring act attracted the attention of Zhang Guoliang who ordered General Tidu Zhang Youliang(張玉良), in command of 36,000 troops, to track Li's corps. Li routed Zhang's troops and crippled the Army Group Jiangnan. When Zhang Youliang arrived in Hangzhou he believed that Li was occupying the city but Li's corps had left two days earlier on March 19th and attacked another city while waiting for reinforcements.

In Nanjing Hong Rengan ordered Chen Yucheng's troops to cross the river. Chen commanded over 100,000 forces along the river and on 29 April he received the signal to attack from Hong Rengan and began the crossing.

Zeng Guofan
When Chief commander Zhang Guoliang and Imperial Inspector Minister Her Chyun died the Qing government promoted Zeng Guofan which changed the course of the war in favor of the Qing and their western allies.