This map is part of a series of 19 animated maps showing the history of Europe's colonial expansion, 1820-1939.
By the mid 19th century, Vietnam – or the Empire of Annam – was worried about the expansion of Western imperialism. It opted for a policy of closing its borders and established closer ties with its Chinese suzerain.
Almost all the Laotian principalities were dominated by Siam, while Cambodia seemed to disappear under the Dual Protectorate administered by Siam and Vietnam.
France found a number of arguments for justifying its intervention: the protection of missionaries and Vietnamese Christians, the need for strategic bases linking India, China and the Pacific, and commercial interests for which Indochina provided a key gateway to the Chinese markets.
Between 1859 and 1867, France took control of Cochin China and offered its protection to the King of Cambodia, who was only too pleased to shrug off Siam’s tutelage.
However at that same period, Garnier and Doudart de Lagrée travelled up the Mekong River and revealed that it did not give access to China, France then decided to explore other options offered by the Red River.
At first, France hesitated over an attack on Tonkin but forced Emperor Tu Duc to sign a first one-sided treaty in 1874. This gave the French access to three ports and to navigation of the Red River.
Nevertheless, the Chinese emperor’s decision to reject the treaty gave the French army a good reason for attacking China : two later treaties placed Annam and Tonkin under a French Protectorate.
Facing resistance from the Annam Court and from China, the French looted Hué and attacked China which then recognized the French Protectorate.
In 1887, French Indochina was created. The Protectorate for the Laotian principalities was added in 1893 as were Guangxi Zhuang, leased from China in 1898, and territories ceded by Siam between 1902 and 1907.
However, France had difficulty controlling all this territory: revolts involving supporters of King Norodom broke out in Cambodia, and further uprisings broke out in Annam and Tonkin in the name of the young Emperor Ham Nghi. The last of these monarchist rebellions was the unsuccessful revolt by Emperor Duy Tan at Hué in 1916.
But more modern forms of nationalism were beginning to emerge, especially in Vietnam. The hesitant or repressive attitude of the colonial authorities, more preoccupied by law and order and economic development, made these movements more radical.
Misery and the agitations of these movements launched the great uprisings of 1930: peasant demonstrations in Cochin China, mutiny of the garrison at Yen Bay, revolt by Soviet peasants in Nghetinh.
Violent repression led to the arrest of the ringleaders and filled the penal colony at Poulo Condor.
Until 1939, all reforms were blocked, mostly because of intransigence from the colonials and obstructionism by the administration.