Nuon Chea was born Lau Ben Kon in 1927 in Battambang Province, Cambodia.
He completed his secondary education in Bangkok, Thailand, under the name Long Ruot. In 1945 Nuon Chea enrolled as a law student at Bangkok's Thamassat University, where he earned a scholarship, and worked part time for Thailand's Foreign Ministry before returning to Cambodia. While he was in Thailand, Chea joined and became a member of the Communist party of Thailand; he became a member of Indochinese Communist Party (ICP) in 1949. ICP was founded by Ho Chi Minh, Vietnamese's leader, in 1930. In 1952 Nuon Chea went to Vietnam and underwent some political training.
After Cambodia gained independence from France in 1953; especially after the dissolution of the ICP, Nuon Chea helped to set up Cambodia communist party - Kampuchean People's Revolutionary Party (KPRP). He was deputy general secretary to first Tou Samouth and later Sarloth Sar/Pol Pot.
Chea was vice president of the Khmer Rouge's military command and chief of its political wing as it fought to power against U.S.-backed Khmer Republic of president Lon Nol between 1970 and 1975.
The Khmer Rouge captured Phnom Penh (Cambodia capital) on April 17, 1975. Immediately after its victory, the Khmer Rouge ordered the evacuation of all cities and towns, sending the entire urban population out into the countryside to till the land. The Cambodia's holocaust thus commented, in which more than one million Cambodians perished three years later.
On October 9, 1975 at the Khmer Rouge standing committee meeting to allocate task for running the country, Nuon Chea was responsible for party organizational work and education. In April 1976 Chea became president of People's Representative Assembly (Khmer Rouge's parliament), in which he served until January 7, 1979 when the Khmer Rouge was ousted from power by the Vietnamese invasion.
Nuon Chea served briefly in 1976 as Khmer Rouge's Democratic Kampuchea prime minister when Pol Pot (Brother Number One) resigned for reason of ill health.
In the Khmer Rouge leadership hierarchy, Nuon Chea was second (Brother Number Two) to Pol Pot. He is regarded by historians and scholars was the ideological guru of the Khmer Rouge. Nuon Chea was blamed for many brutal purges, in which thousands were killed. Chea, however, never revealed anything personal in public; his anonymity reflected in his statement to the visiting Danish delegation "secret work is fundamental...."
More than a decade since the Khmer Rouge was ousted from power in 1979, nothing much is known about Nuon Chea; he has always chosen to remain in the shadows. Not until the mid-1990s when Phnom Penh government pursued to put him and the remaining Khmer Rouge leaders on trial that his name is widely known, especially to Cambodian.
On December 25, 1998 Nuon Chea and Khieu Samphan surrendered to the Cambodian government; they were warmly received by the government leader and allowed to live free in the semi-autonomous region run by their former comrade, Ieng Sary.