Nuon Chea was born on July 7, 1926 in Voat Kor, Battambang, Cambodia. He was married to Ly Kim Seng. He died on August 4, 2019 in Phnom Penh, Cambodia.
He was the chief ideologist of the Khmer Rouge and called Brother Number Two, second only to Pol Pot. He was condemned in 2007 for crimes against humanity.