Who Controlled Indochina in 1886? French Colonial Expansion

By 1886, France had established firm control over most of Indochina. Vietnam was formally annexed on June 6, 1884, following the Treaty of Huế, which established a French protectorate over Annam and Tonkin. Cochinchina (southern Vietnam) had been a French colony since 1862.

However, the region was not entirely under French authority. China maintained influence in northern Vietnam and parts of Laos, while Siam (modern-day Thailand) controlled territories to the west, including parts of Cambodia and the right bank of the Mekong. The Franco-Siamese War of 1893 would later force Siam to cede Laos to France, completing the formation of French Indochina.

Thus, in 1886, Indochina was a contested mosaic: predominantly French, with Chinese and Siamese presence in border regions.