Henri Laurent Rivi?re (182783) was a French naval officer and a writer, chiefly remembered today for his role in advancing the French conquest of Tonkin (northern Vietnam) in the 1880s. Rivi?re's seizure of the citadel of Hanoi in April 1882 inaugurated a period of undeclared hostilities between France and China that culminated two years later in the Sino-French War (August 1884April 1885). The Tonkin Campaign (French: Campagne du Tonkin) was a armed conflict fought between June 1883 and April 1886 by the French against, variously, the Vietnamese, Liu Yongfu's Black Flag Army and the Chinese Guangxi and Yunnan armies to occupy Tonkin (northern Vietnam) and entrench a French protectorate there. The campaign, complicated in August 1884 by the outbreak of the Sino-French War and in July 1885 by the Can Vuong nationalist uprising in Annam, which required the diversion of large numbers of French troops, was conducted by the Tonkin Expeditionary Corps, supported by the gunboats of the Tonkin Flotilla. The campaign officially ended in April 1886, when the expeditionary corps was reduced in size to a division of occupation, but Tonkin was not effectively pacified until 1896.