Diarchy (or dyarchy), from the Greek "δύο", and αρχειν, "to rule," is a form of government in which two diarchs are the heads of state. In most diarchies, the diarchs hold their position for life and pass the responsibilities and power of the position to their children or family when they die. The diarchy is one of the oldest types of government and has been in existence for centuries. Diarchies are known from ancient Sparta, Rome, Carthage as well as from Germanic and Dacian tribes. Several ancient Polynesian societies exhibited a diarchic political structure as well. Ranks in the Inca Empire were structured in moieties, with two occupants of each rank, but with different prestige, one hanan (upper) and one hurin (lower). In modern usage diarchy means a system of dual rule, whether this be of a government or of an organisation. Such 'diarchies' are not hereditary. Examples of modern forms are the governments of San Marino and Northern Ireland. The Montagu-Chelmsford reforms of British India prescribed a "dyarchy" of ministers who were individually responsible to the legislature, and the Australian Defence Organisation operates as a diarchy. Andorra is the only present country to retain two diarchs, known as co-princes, as head of state.

Current diarchies

Andorra

Andorra is a co-principality. The Diarchs are the President of France and the Bishop of Urgell. The current co-princes are Nicolas Sarkozy and Joan Enric Vives Sicília respectively.

Former diarchies

Swedish monarchs

• Erik and Alrik
• Yngvi and Alf
• Björn at Hauge and Anund Uppsale
• Eric the Victorious and Olof (II) Björnsson
• Eric the Victorious and Olof Skötkonung
• Haakon the Red and Ingold I

English, Scottish and Irish monarchs

• William III and Mary II

Other usage

Australian Defence Organisation

The Australian Defence Organisation (ADO) is an Australian Government organisation which consists of the Australian Defence Force (ADF) and the civilian Department of Defence personnel supporting the ADF. The Chief of the Defence Force and the Secretary of the Department of Defence jointly manage the ADO under a "diarchy", a term used to describe the relationship between the Chief of the Defence Force and the Secretary, both of whom report directly to the Minister for Defence. The ADO diarchy is a governance structure unique in the Australian Commonwealth public service.

India

Due to shaky governments due to the coalition governments in the recent past, Diarchies have been both successfully and unsuccessfully tested in India. Some successful examples include the current government in Jammu and Kashmir and Karnataka. A failed one was in 1995 in Uttar Pradesh between the BSP and the BJP.

Italy

Diarchia is also the name applied to the form of government during the fascist period in Italy when the king was still in office as head of state but all power was in the hands of Benito Mussolini.

Northern Ireland

The positions First Minister and deputy First Minister operate as a diarchy and have done so since 1998. The devolved government of Northern Ireland established after the Belfast Agreement in 1998 has a system whereby the Assembly elects two leaders, one from each of the two main communities. These two leaders actually have identical powers even though they are called First Minister and Deputy First Minister respectively and serve jointly; if one ceases to hold office so must the other.

See also

• Monarchy
• Monarch
• Duumvirate

References and notes