When did South Vietnam exist?

South Vietnam existed 1955–1975. On this map it is drawn 1956–1966, 1973–1975.

How large was South Vietnam?

At its greatest extent drawn on this map, South Vietnam covered about 181,000 km². That is the largest area the border data gives it across the years it is drawn, not necessarily its greatest extent in history.

Southeast Asia · The modern states

South Vietnam

Republic · 1955–1975

South Vietnam grew out of the French-backed State of Vietnam (1949) under ex-emperor Bảo Đại. Ngô Đình Diệm became prime minister in June 1954 and, after the Geneva partition, deposed Bảo Đại through a referendum in October 1955 — officially winning 98% of the vote, and 133% in Saigon — proclaiming the Republic of Vietnam on 26 October 1955.

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Type: Republic
Existed: 1955–1975
Shown on the map: 1956–1966, 1973–1975 (2 periods)
Peak area: 181k km²
Region: Southeast Asia

Origins & foundation

Political history & notable leaders

Diệm refused to hold the 1956 reunification elections, ruled through his family under the ideology of "Personalism", and alienated the Buddhist majority; the 1963 Buddhist crisis ended with his murder in a US-backed coup on 1 November 1963. A succession of military juntas (Dương Văn Minh, Nguyễn Khánh, then Nguyễn Cao Kỳ and Nguyễn Văn Thiệu) ruled until the "Second Republic" constitution of 1967, under which Thiệu won the presidency with 34% of the vote. Thiệu governed until resigning on 21 April 1975 and fleeing to Taiwan; Dương Văn Minh, installed as a last-minute president, surrendered Saigon on 30 April 1975.

Economy, culture & society

South Vietnam covered 173,809 km² with 19.6 million people (1974). Its war-dependent economy floated on US aid; Saigon became a swollen metropolis while the countryside was devastated by bombing, defoliants and forced urbanisation.

Territorial extent & key events

The republic controlled the territory south of the 17th parallel, plus the Paracel and Spratly claims — China seized the Paracels from it in 1974. Recognised by 95 countries, its UN admission was vetoed by the Soviet Union in 1957.

Conflicts & turning points

The NLF insurgency from 20 December 1960, the Gulf of Tonkin incident (1964) and US escalation, the Tet Offensive (1968), the Cambodia (1970) and Laos (Lam Son 719, 1971) incursions, the 1972 Easter Offensive and the January 1973 Paris Accords (followed by US withdrawal in March 1973) defined its trajectory. After Phước Long fell in December 1974, the 1975 spring offensive — Ban Me Thuot, Xuân Lộc — collapsed the state within weeks.

Legacy & present-day status

South Vietnam was replaced by a Provisional Revolutionary Government and formally merged with the North on 2 July 1976. It survives in the memory and flags of the overseas Vietnamese diaspora.

Common questions

What was South Vietnam?: South Vietnam grew out of the French-backed State of Vietnam (1949) under ex-emperor Bảo Đại. Ngô Đình Diệm became prime minister in June 1954 and, after the Geneva partition, deposed Bảo Đại through a referendum in October 1955 — officially winning 98% of the vote, and 133% in Saigon — proclaiming the Republic of Vietnam on 26 October 1955.
When did South Vietnam exist?: South Vietnam existed 1955–1975. On this map it is drawn 1956–1966, 1973–1975.
How large was South Vietnam?: At its greatest extent drawn on this map, South Vietnam covered about 181,000 km². That is the largest area the border data gives it across the years it is drawn, not necessarily its greatest extent in history.
Where was South Vietnam?: The republic controlled the territory south of the 17th parallel, plus the Paracel and Spratly claims — China seized the Paracels from it in 1974. Recognised by 95 countries, its UN admission was vetoed by the Soviet Union in 1957.
Who ruled South Vietnam?: Diệm refused to hold the 1956 reunification elections, ruled through his family under the ideology of "Personalism", and alienated the Buddhist majority; the 1963 Buddhist crisis ended with his murder in a US-backed coup on 1 November 1963. A succession of military juntas (Dương Văn Minh, Nguyễn Khánh, then Nguyễn Cao Kỳ and Nguyễn Văn Thiệu) ruled until the "Second Republic" constitution of 1967, under which Thiệu won the presidency with 34% of the vote.
How did South Vietnam end?: South Vietnam was replaced by a Provisional Revolutionary Government and formally merged with the North on 2 July 1976. It survives in the memory and flags of the overseas Vietnamese diaspora.
What did the economy and culture of South Vietnam rest on?: South Vietnam covered 173,809 km² with 19.6 million people (1974). Its war-dependent economy floated on US aid; Saigon became a swollen metropolis while the countryside was devastated by bombing, defoliants and forced urbanisation.

Sources

Every source below was consulted while writing this entry.

Wikipedia: South Vietnam en.wikipedia.org/wiki/South_Vietnam

This entry was written from the sources above and last updated 10 September 2026.

This entry was researched and drafted with AI from the sources above, and has not been reviewed by a historian. How entries are made

Text available under CC BY-SA 4.0: reuse it with a credit to The World Through Time and a link to this page. Passages drawing on the Wikipedia articles listed above are also licensed CC BY-SA 4.0 by their contributors.

Border geometry for the map itself comes from Cliopatria v0.12 (Seshat Global History Databank, CC-BY-4.0).

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