The Battle of Hanoi was fought on 20 November 1873 between France and Việt Nam. A French expeditionary force composed of 140 sailors, 30 marines and 8 officers under Lieutenant Francis Garnier captured, without orders, the provincial capital Hanoi, where they had been sent by France on a diplomatic mission. The capture of the city became the starting point of an unsanctioned military campaign by Lieutenant Garnier and his men, who then proceeded to conquer most of the Tonkin region over the course of December 1873.