Nguyễn Văn Nhung was an officer in the Army of the Republic of Vietnam (ARVN). After joining the French Army in 1944 during the colonial era of Vietnam, he soon met and became the aide-de-camp and bodyguard of Dương Văn Minh, and spent the rest of his career in this role as Minh rose up the ranks to become a general. Nhung and Minh later transferred to the French-backed Vietnamese National Army (VNA) during the First Indochina War and he became an officer; the VNA then became the ARVN after the creation of the Republic of Vietnam. A soft-spoken man, Nhung was a professional military assassin best known for his role in the November 1963 coup d'état led by Minh that ousted President Ngô Đình Diệm from office.

Dương Văn Minh, popularly known as Big Minh, was a South Vietnamese politician and a senior general in the Army of the Republic of Vietnam (ARVN) and a politician during the presidency of Ngô Đình Diệm. In 1963, he became chief of a military junta after leading a coup in which Diệm was assassinated. Minh lasted only three months before being toppled by Nguyễn Khánh, but assumed power again as the fourth and last President of South Vietnam in April 1975, two days before surrendering to North Vietnamese forces. He earned his nickname "Big Minh", because he was approximately 1.83 m (6 ft) tall and weighed 90 kg (198 lb).