About: French protectorate of Cambodia

In 1863, Cambodia under king Norodom became a protectorate of France. In October 1887, the French announced the formation of the Union Indochinoise, which at that time comprised Cambodia, already an autonomous French possession, and the three regions of Vietnam. In 1893, Laos was annexed after the French threatened Siam's King Chulalongkorn with war, thereby forcing him to give up the territory.