Khmer Rouge was the name given to the followers of the Communist Party of Kampuchea in Cambodia. It was formed in 1968 as an offshoot of the Vietnam People's Army from North Vietnam. Pol Pot was the leader of the Khmer Rouge and dictator of Cambodia.
The Khmer Rouge government arrested, tortured, and eventually executed anyone suspected of belonging to several categories of supposed "enemies". One of then included professionals and intellectuals.
This included almost everyone with an education, or even English-speaking people or people wearing glasses (which, according to the regime, meant that they were literate).
Ironically, Pol Pot himself was a university-educated man with a taste for French literature and was also a fluent French speaker. Many artists—including musicians, writers, and filmmakers—were executed.