The communist movement in Vietnam and Cambodia began before World War II with the founding of the Indochinese Communist Party (ICP), almost exclusively dominated by the Vietnamese, originally meant to fight French colonial rule in Indochina. In 1941, Nguyen Ai Quoc (commonly known by his alias; Ho Chi Minh) founded the Viet Nam Doc Lap Dong Minh Hoi, or the Viet Minh (later as the Viet Cong). When the Japanese were defeated at the end of World War II, he initiated the First Indochina War against the French. During this time, the Vietnamese forces made extensive use of Cambodian territory to transport weapons, supplies, and troops. This relationship lasted throughout the Vietnam War, when the Vietnamese communists used Cambodia as a transport route and staging area for attacks on South Vietnam. In 1951, Vietnam guided the establishment of a separate Cambodian communist party, the Kampuchean People's Revolutionary Party (KPRP), which allied with a nationalist separatist Cambodian movement, the Khmer Serei (Free Khmers), in order to pursue independence. In accordance with the 1954 Geneva Accords negotiating the end of the French domination, newly created communist North Vietnam pulled all of its Viet Minh soldiers and cadres out of Cambodia. Since the KPRP was staffed primarily by ethnic Vietnamese or Cambodians under its tutelage, approximately 5,000 communist cadres went with them. The power vacuum as the Vietnamese communists left in their wake in Cambodia was soon filled by the return of a young group of Cambodian communist revolutionaries, many of whom received their education in France. After the removal of Sihanouk from power in March 1970, the leader of the new Khmer Republic, Lon Nol, despite being anti-communist and ostensibly in the "pro-American" camp, backed the FULRO against all Vietnamese, both anti-communist South Vietnam and the communist Viet Cong. Following the 1970 coup, thousands of Vietnamese were massacred by forces of Lon Nol. Many of the dead were dumped in the Mekong River. 310,000 ethnic Vietnamese fled Cambodia as a result. The Khmer Rouge government adopted the mysterious term Angkar, or 'the organisation', and the identities of its leaders, politicians and party cadres. A major point of departure between the Khmer Rouge faction and the Vietnam-aligned Communist Party of Kampuchea (CPK), which has favored more classical Marxism–Leninist ideology, was the Khmer Rouge's embrace of a nationalistic form of Maoism, one of the few major communist parties along with China and North Korea following the Fall of Phnom Penh and the Fall of Saigon in April 1975.