From Wikipedia

 Inside Vietnam

 France began its conquest of Indochina in the late 1850s, and completed pacification by 1893. The Treaty of Huế, concluded in 1884, formed the basis for French colonial rule in Vietnam for the next seven decades. In spite of military resistance, most notable by the Can Vuong of Phan Dinh Phung, by 1888, the area of the current-day nations of Cambodia and Vietnam was made into the colony of French Indochina (Laos was added later). Various Vietnamese opposition movements to the French rule existed during this period, such as the Viet Nam Quoc Dan Dang who staged the failed Yen Bai mutiny in 1930, but none were ultimately as successful as the Viet Minh common front, controlled by the Communist Party of Vietnam, founded in 1941 and funded by US and Chinese Nationalist Party in its fight against Japanese occupation.