History of Cambodia By dataylor Sep 1, 1863 Cambodia comes under the French Rule Sep 1, 1941 Cambodia is occupied by Japan during WWII Sep 1, 1953 Cambodia declares independence from France Sep 1, 1975 Khmer Rouge occupy Phnom Penh Sep 1, 1975 Cambodia is renamed to Kampuchea Sep 1, 1977 Fighting breaks out with Vietnam Sep 1, 1978 Vietnamese forces invade Cambodia Sep 1, 1979 Vietnamese take over Phnom Penh Sep 1, 1979 Pol Pot and Khmer Rouge forces flee to the borders with Thailand Sep 1, 1989 Vietnamese troops withdraw and the country is re-named the State of Cambodia Sep 1, 1997 The Khmer Rouge put Pol Pot on trial and sentence him to life imprisonment1998 Pol Pot dies.