 A few years later, French troops landed in northern Vietnam (which they called Tonkin) and captured Hà Nội twice in 1873 and 1882.The French managed to keep their grip on Tonkin although, twice, their top commanders Francis Garnier and Henri Rivière, were ambushed and killed fighting pirates of the Black Flag Army hired by the mandarins.France assumed control over the whole of Vietnam after the Tonkin Campaign (1883–1886).