[1] In common with several other future members of the Khmer Rouge, he studied at the Lycee Sisowath, though unlike the majority of his colleagues at that school, he was from a poor background: his father was a peasant who grew rice and tobacco.
Yuon, who enjoyed great personal popularity - he was described as having "truly astounding physical and intellectual strength"[3] - became an important figure in the community of radical Cambodian expatriates in Paris.
[4] In 1952, along with Saloth Sar, Ieng Sary, and other leftists, Yuon gained notoriety by sending an open letter to the then-King Norodom Sihanouk calling him the "strangler of infant democracy."
Sihanouk, by now Prime Minister of an independent Cambodia, invited a number of prominent leftists, including Hou Yuon, into his Sangkum party and government to provide a balance to the right-wing.
However, after the Samlaut Uprising of 1967, Yuon was accused by Sihanouk of stirring up unrest, and threatened with arrest and possible execution: he fled to join the communist maquis, led by Saloth Sar (Pol Pot), Ieng Sary and Son Sen, in the forests.
Yuon was made Minister for Cooperatives, and caused serious rifts between himself and other members of the Khmer Rouge leadership by protesting at the speed with which collectivisation was being carried out in the 'liberated' areas.
[8] His previous tendency to openly criticise the regime's excesses appears to have continued unabated: when entering Phnom Penh, which had been divided into several sectors each run by the administration of a different zone of the country, he is reported to have remarked "It's Berlin!".