French protectorate of Cambodia
The French protectorate of Cambodia was the period of French colonial rule in Cambodia within French Indochina, a collection of Southeast Asian protectorates within the French colonial empire. The protectorate was established in 1863 when the Cambodian King Norodom requested the establishment of a French protectorate over his country, meanwhile Siam (modern Thailand) renounced suzerainty over Cambodia and officially recognised the French protectorate on Cambodia.
Source: Wikipedia — French protectorate of Cambodia (CC BY-SA 4.0)