Ta Mok, also known as Nguon Kang, was a Cambodian military chief and soldier who was a senior figure in the Khmer Rouge and the leader of the national army of Democratic Kampuchea. He was also known as "Brother Number Five" or "the Butcher". He was captured along the Thailand-Cambodia border in March 1999 by Cambodian government forces while on the run with a small band of followers and was held in government custody until his death in 2006 while awaiting his war crime trial.

The Khmer Rouge is the name that was popularly given to members of the Communist Party of Kampuchea (CPK) and by extension to the regime through which the CPK ruled Cambodia between 1975 and 1979. The name was coined in the 1960s by then Chief of State Norodom Sihanouk to describe his country's heterogeneous, communist-led dissidents, with whom he allied after his 1970 overthrow.