The First Indochina War began in French Indochina on December 19, 1946, and lasted until July 20, 1954. Fighting between French forces and their Việt Minh opponents in the south dated from September 1945.
In 1941, the Việt Minh, a nationalist liberation movement based on a Communist ideology, emerged under the Vietnamese revolutionary leader Hồ Chí Minh. The Việt Minh sought independence for Vietnam from France and the end of the Japanese occupation. Following the military defeat of Japan and the fall of its puppet Empire of Vietnam in August 1945, anarchy, rioting and murder were widespread since Saigon’s administrative services collapsed. The Việt Minh occupied Hanoi and proclaimed a provisional government, which asserted national independence on 2 September.
Earlier, in July 1945, the Allies had decided to divide Indochina at the 16th parallel to allow Chiang Kai-shek of the Republic of China to receive Japanese surrender in the north while Lord Louis Mountbatten of the British would receive the surrender in the south, with the Allies agreeing that Indochina belonged to France.
However, as the French were weakened as a result of German occupation, the British-Indian forces together with the remaining Japanese Southern Expeditionary Army Group were used to maintain order and to help France re-establish control through the 1945–1946 War in Vietnam. Hồ Chí Minh at the time chose a moderate stance to avoid military conflict with France by which he asked the French to withdraw their colonial administrators and asked for aid from French professors and engineers to help build a modern independent Vietnam. These requests, including the idea for independence, however, could not be accepted by the Provisional Government of the French Republic, which dispatched the French Far East Expeditionary Corps instead to restore colonial rule, causing the Việt Minh to launch a guerrilla campaign against the French in late 1946. Matters also turned worse when the Republic of China gradually fell to the communists in the Chinese Communist Revolution. The resulting First Indochina War lasted until July 1954. The defeat of French and Vietnamese loyalists in the 1954 battle of Điện Biên Phủ allowed Hồ Chí Minh to negotiate a ceasefire from a favorable position at the subsequent Geneva Conference.
the colonial administration was ended and French Indochina was dissolved under the Geneva Accords of 1954 into three countries: Vietnam and the kingdoms of Cambodia and Laos. Vietnam was further divided into North and South administrative regions at the Demilitarised Zone, approximately along the 17th parallel north, pending elections scheduled for July 1956. A 300-day period of free movement was permitted, during which almost a million northerners, mainly Catholics, moved south, fearing persecution by the communists. The partition of Vietnam was not intended to be permanent by the Geneva Accords, which stipulated that Vietnam would be reunited after elections in 1956. However, in 1955, the State of Vietnam’s Prime Minister, Ngô Đình Diệm toppled Bảo Đại in a fraudulent referendum organized by his brother Ngô Đình Nhu, and proclaimed himself president of the Republic of Vietnam. At that point, the internationally recognized State of Vietnam effectively ceased to exist and was replaced by the Republic of Vietnam in the south and the Hồ Chí Minh’s Democratic Republic of Vietnam in the north. Read about the Vietnam War.