French Indochina was a federation of French colonies and protectorates in Southeast Asia, part of the French colonial empire. It consisted of Cochin China, Tonkin, Annam (all of which now form Vietnam), Laos and Cambodia.
France assumed sovereignty over Annam and Tonkin after the Franco-Chinese War (1884–1885). French Indochina was formed in October 1887 from Annam, Tonkin, Cochin China, and the Kingdom of Cambodia; Laos was added in 1893. The capital of French Indochina was Hanoi. The French formally left the local rulers in power (Emperors of Vietnam, Kings of Cambodia, Kings of Luang Prabang), but in fact gathered all powers in their hands, the local rulers acting only as figureheads.
In September 1940, during World War II, Vichy France (which had just submitted to Nazi Germany) granted Japan's demands for military access to Tonkin. Immediately this allowed Japan better access to China. The Japanese kept the French bureaucracy and leadership in place to run French Indochina.
On March 9, 1945, with France liberated, Germany in retreat, and the USA ascendant in the Pacific, Japan decided to take complete control of French Indochina. The Japanese kept power until the news of their government's surrender came though in August, after the atomic bombs were dropped on Hiroshima and Nagasaki.
After the war, France attempted to reassert itself in the region, but came into conflict with the Viet Minh, an organization of Communist Vietnamese nationalists under French-educated Ho Chi Minh. During World War II, the USA had supported the Viet Minh in resistance against the Japanese; the group was in control of the country apart from the cities since the French gave way in March 1945. After persuading Emperor Bao Dai to abdicate in his favour, Ho Chi Minh declared independence for the Democratic Republic of Vietnam. But before the end of September, a force of British, French and Indian soldiers, along with captured Japanese troops, restored French control. Bitter fighting ensued in the First Indochina War. In 1950 Ho again declared an independent Democratic Republic of Vietnam, which was recognized by the fellow Communist governments of China and the Soviet Union.
Fighting lasted until March 1954, when the Viet Minh won the decisive victory against French forces at the gruelling Battle of Dien Bien Phu. This led to the partition of Vietnam into the Democratic Republic of Vietnam in the North, under Viet Minh control, and the State of Vietnam in the South, which had the support of the USA, the United Kingdom, and France. The events of 1954 also marked the end of French involvement in the region, and the beginnings of serious US commitment to South Vietnam which led to the Vietnam War.

 

 

The postage stamps of French Indochina begin on May 16, 1886, with the overprinting of "5" or "5 C. CH." on the generic stamps of the French Colonies, for use in Cochin China (mainly Saigon).
The 1889 unification of colonial administration first resulted in surcharges in January 1889, on the 35c French Colonies stamp, reading INDO-CHINE 1889 / 5 / R - D (8 January) and INDO-CHINE 89 / 5 / RD (10 January), where the "R" referred to the colonial governor P. Richaud, and the "D" to the postmaster at Saigon, General P. Demars.
In 1892 the first regular stamps of Indochina were issued as part of the standard Navigation and Commerce series used by the other colonies, and inscribed INDO-CHINE.
Subsequent issues included an attractive and artistic set featuring native women (1907), a surcharged set of 1919 necessitated by the changeover from centimes and francs to cents and piasters in the previous year, and a reprinted set valued in the new currency, starting with a 1/10-cent denomination.
Sets featuring local sights appeared in 1927 and 1931, and one in 1936 depicting the various native emperors and kings in Indochina, followed by a variety of commemoratives honoring notable figures, up to a last airmail stamp issued on July 4, 1949, commemorating the 75th anniversary of the Universal Postal Union.