Ngô Đình Diệm in the context of 1963 South Vietnamese coup d'état

The State of Vietnam (Vietnamese: Quốc gia Việt Nam; chữ Hán: 國家越南; French: État du Viêt-Nam) was a state in Southeast Asia that existed from 1949 until 1955, first as an associated state of the French Union and later as an independent state (from 20 July 1954 to 26 October 1955). The state claimed authority over all of Vietnam during the First Indochina War, although large parts of its remote territory were controlled by the Democratic Republic of Vietnam.

The State of Vietnam was formed in 1949 within the framework of the French Union as a compromise between Vietnamese nationalists and the French, in opposition to the communists. It gained international recognition in 1950 and aligned politically with the Western Bloc. Former emperor Bảo Đại became Chief of State. Following the 1954 Geneva Accords between the communist Viet Minh and the French, the State of Vietnam lost its remaining foothold in the northern half of the country, where most rural areas were already controlled by the Viet Minh. Ngô Đình Diệm was appointed prime minister the same year and—after having ousted Bảo Đại in 1955—became president of the Republic of Vietnam.

Dương Văn Minh (Vietnamese: [jɨəŋ van miŋ̟] or [zɨəŋ van miŋ̟]; 16 February 1916 – 6 August 2001), 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).

Born in Tiền Giang province in the Mekong Delta region of southern Vietnam, Minh joined the French Army at the start of World War II, and was captured and tortured by the Imperial Japanese, who invaded and seized French Indochina. After his release, he joined the French-backed Vietnamese National Army (VNA) and was imprisoned by the communist-dominated Viet Minh before breaking out. In 1955, after Vietnam was partitioned and the State of Vietnam controlled the southern half under Prime Minister Ngô Đình Diệm, Minh led the VNA in decisively defeating the Bình Xuyên paramilitary crime syndicate in street combat and dismantling the Hòa Hảo religious tradition's private army. This made him popular with the people and Diệm, but the latter later put him in a powerless position, regarding him as a threat.