After the Second Opium War in 1856, the Anglo-French coalition captured Beijing in 1860 and occupied the Yuanmingyuan on October 6.

Before the Yuanmingyuan was destroyed
The Chinese defenders were outnumbered, and Wen Feng, the minister in charge of the Yuanmingyuan, committed suicide by throwing himself into Fuhai, and Chang Concubine, who lived in the garden, was frightened and died. Two days after the British and French armies had looted, they marched into the city. On October 11, the British army sent more than 1,200 cavalry and an infantry regiment to loot the Yuanmingyuan again, and the British Plenipotentiary, James Bruce, included the burning of the Yuanmingyuan as a precondition for the Qing government on the pretext that the Qing government had imprisoned Pasha Li and others in the Yuanmingyuan. On October 18, 3,500 British troops rushed into the Yuanmingyuan and set fire to the Yuanmingyuan, the fire was not extinguished for three days, the Yuanmingyuan and the nearby Qingyi Garden, Jingmingyuan, JingyiYuan, Changchun Garden and Haidian Town were burned to rubble, and nearly 300 eunuchs, palace women and craftsmen were buried in the sea of fire in Anyou Palace. It has become a rare atrocity in the history of world civilization.
After the destruction of the Old Summer Palace
Burning the Yuanmingyuan is a phrase that people are accustomed to. In fact, the real concept of burning the Yuanmingyuan is not only to burn the Yuanmingyuan, but to burn the Royal Three Mountains and Five Gardens in western Beijing. The scope of the burning was far larger than that of the Old Summer Palace.
The three mountains and five gardens are: Wanshou Mountain, Yuquan Mountain, Xiangshan Three Mountains, Qingyi Garden, Yuanmingyuan, Changchun Garden, Jingmingyuan, Jingyi Garden five gardens.
In history, there have been two times when the invading army burned the Yuanmingyuan. The first burning of the Yuanmingyuan was (1860), when the British and French forces invaded Beijing. The Anglo-French forces burned and looted everywhere, barbarically looted, and burned the world-famous Yuanmingyuan, and most of the temple buildings in the park were destroyed by fire. When the Anglo-French forces burned the Yuanmingyuan, the original intention was to raz it to the ground, but because the area of the Yuanmingyuan garden was too large, the scenic spots were scattered, and the water was vast, some remote places and water attractions survived. According to the winter survey of the twelfth year of Tongzhi (1873), there are still 13 buildings in the park. For example, Pengdao Yaotai and Tibetan Boat Dock in the Yuanmingyuan, the Grand Palace Gate and Zhengjue Temple in Qichun Garden.
The second burning of the Yuanmingyuan was in 1900, when the Eight-Power Alliance invaded Beijing and set fire to the Yuanmingyuan again, causing the 13 remaining royal palace buildings here to be plundered and burned.
In literary works, it seems that the sin of burning the Yuanmingyuan was blamed on the incompetence of Empress Dowager Cixi to bow down to the government. It sounds like there's some truth to it, but it's not exact. Countless facts in history have shown that a poor, backward, and weak country and nation can only be in a position of oppression, exploitation, humiliation and plunder. The history of burning the Yuanmingyuan proves once again that a poor, backward, and weak country will be beaten.
Sons and daughters of China, do not forget the national shame.