Union of South Africa

state in southern Africa from 1910 to 1961, predecessor to the Republic of South Africa

The Union of South Africa is the country that came before the current Republic of South Africa. It was formed on May 31st, 1910 when the British Cape Colony and the Natal Colony unified with the defeated Boer republics of the South African Republic and the Orange Free State. The provinces of the union were called, respectively, as the Cape Province, the Natal Province, the Transvaal Province, and the Orange Free State Province. After World War I, the former German colony of German South West Africa was put under administration of the Union of South Africa as a League of Nations mandate and was treated like another province. It was a Commonwealth realm, which means that it was a constitutional monarchy with the British monarch (king or queen) as the head of state.

Union of South Africa
Unie van Suid-Afrika
Unie van Zuid-Afrika
Coat of arms of South Africa
Coat of arms
Motto: Ex Unitate Vires
(Latin: From Unity, Strength)
Anthem: Die Stem van Suid-Afrika
"The Call of South Africa"
Location of the Union of South Africa. South West Africa shown as disputed area (administered as 5th province of the Union).
Location of the Union of South Africa. South West Africa shown as disputed area (administered as 5th province of the Union).
CapitalCape Town (legislative)
Pretoria (administrative)
Bloemfontein (judicial)
Pietermaritzburg (archival)
Common languagesDutch, English, Afrikaans (after 1925)
GovernmentConstitutional monarchy
• 1910-1936
George V
• 1936
Edward VIII
• 1936-1952
George VI
• 1952-1961
Elizabeth II
• 1910-1914
The Viscount Gladstone
• 1959-1961
Charles Robberts Swart
Prime Minister 
• 1910-1919
Louis Botha
• 1919-'24, 1939-1948
Jan Smuts
• 1924-1939
J.B.M. Hertzog
• 1948-1954
D.F. Malan
• 1954-1958
J.G. Strijdom
• 1958-1961
H.F. Verwoerd
House of Assembly
• Union
31 May 1910
11 December 1931
• Republic
31 May 1961
19612,045,320 km2 (789,700 sq mi)
• 1961
CurrencySouth African pound
ISO 3166 codeZA
Preceded by
Succeeded by
British Cape Colony
Colony of Natal
Orange River Colony
Transvaal Colony
South Africa
Today part of South Africa

The Union of South Africa ended on 31 May 1961, when a new constitution came into effect, transforming the Union of South Africa into a republic, under the name "Republic of South Africa". The South Africa's membership of the Commonwealth of Nations also ended, when it became a republic.