55 Days in Peking

The 1963 film 55 Days in Peking stars Charleton Heston, Ava Gardener, and David Niven. From Wikipedia:

55 Days at Peking is a dramatization of the siege of the foreign legations' compounds in Peking (now Beijing) during the Boxer Rebellion which took place in 1900 China. Fed up by foreign encroachment, the Dowager Empress Tzu-Hsi uses the Boxer secret societies to attack foreigners within China, leading to the siege and subsequent direct intervention by foreign expeditionary forces which were dispatched to put down the rebellion. The film concentrates on the defense of the legations from the point of view of the foreign powers, and the title refers to the length of the defense by the colonial powers of the legations district of Peking.