1, in order to cover up the robbery.

2. By burning Yuanmingyuan, the rebellious will of the supreme ruling clique in Qing Dynasty was completely defeated, forcing the Qing government to surrender immediately.

In the tenth year of Xianfeng (1860), after the British and French allied forces captured Beijing, they occupied Yuanmingyuan. China's defenders were outnumbered, and Wenfeng, the chief minister of Yuanmingyuan, committed suicide by throwing himself into Fuhai. Chang Ai, who lived in the garden, was scared to death. With the support of British Prime Minister Pa Max Don, British leader Elgin ordered the burning of Yuanmingyuan. 3500 British troops rushed into Yuanmingyuan and set fire to it. The fire didn't go out for three days, and the Yuanmingyuan and its nearby Qingyi Garden, Jingming Garden, Jingyi Garden, Changchun Garden and Haidian Town were all burned into ruins.