Cambodia, Laos and Vietnam all came under French rule between 1860 and 1900, forming French Indochina. During the 1940-5 Japanese occupation, the communist-led Vietminh movement launched a resistance campaign in northern Vietnam (Tonkin, or Tongking). In 1945 it set up a government in Hanoi. Although the French reoccupied Hanoi in 1946, they faced a long conﬂict with the Vietminh. In 1954, after the Vietminh had trapped a French force at Dien Bien Phu, ceaseﬁre agreements were signed. Vietnam was divided at the 17° North parallel. The French withdrew from North Vietnam, where a communist government was again installed in Hanoi. In South Vietnam the French completed the transfer of sovereignty to the government in Saigon. About 800,000 Vietnamese ﬂed from north to south.