Excerpts from Books and Wikipedia
"Franco-British armies sack the Summer Palace; Treaty of Beijing further erodes Chinese sovereignty." [Fall and Rise of China Guidebook, Timeline] "In 1860, the French and British looted the Summer Palace at the end of the Second Opium War and on October 18, 1860 the British burned down the nearby Old Summer Palace (called the Yuanmingyuan in Chinese). The destruction of the palace was ordered by Lord Elgin, the British High Commissioner to China, and was undertaken in response to the torture and killing of two British envoys, a journalist for The Times, and their escorts. The destruction of large parts of the Summer Palace still evokes strong emotions among some people in China." [Wikipedia]