Li Xiucheng
In June 1860 a Taiping army of 20,000 led by Lai Wenguang had attacked Shanghai and reoccupied it for five months before withdrawing. In early 1861 Li Xiucheng was in control of Zhejiang and Jiangsu provinces, commanding over 600,000 Taiping troops. He aimed to capture the large but isolated city, one of the most important cities under the Qing government and home to an international port. At Li Xiucheng's request the UK and France had promised to maintain neutrality.