This article does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed. (January 2008)

A duumvirate is an alliance between two equally powerful political or military leaders. The term can also be used to describe a state with two different military leaders who both declare themselves to be the sole leader of the state.

The tiny European nation of Andorra is technically a duumvirate, as it is ruled by two co-princes (one of whom is the President of France), although the Andorran prime minister actually wields power as the head of government. Duumvirates in history include the city-states of Carthage, ruled by two mayors, and ancient Rome, ruled by two Consuls.

In the fictional Middle-earth legendarium of author J.R.R. Tolkien, the Black Númenóreans' coastal city of Umbar was typically ruled by a duumvirate.

Some political parties have duumvirates, sometimes, such as is the case of Lindsey German and John Rees in the Socialist Workers Party in Britain.

See also

• Diarchy - rule by two people
• Duoviri - ancient Roman magistracy of two men
• Triumvirate - the equivalent term for three people
• Decemvirate - the equivalent term for ten people