Diarchy (from Greekδι-, di-, "double",[1] and -αρχία, -arkhía, "ruled"),[2][note 1][3]duarchy,[4] or duumvirate[5][note 2] is a form of government characterized by corule, with two people ruling a polity together either lawfully or de facto, by collusion and force. The leaders of such a system are usually known as corulers.[6]
Historically, diarchy particularly referred to the system of shared rule in British India[2] established by the Government of India Acts 1919 and 1935, which devolved some powers to local councils, which had included native Indian representation under the Indian Councils Act 1892. 'Duumvirate' principally referred to the offices of the various duumviri established by the Roman Republic.[5] Both, along with less common synonyms such as biarchy[7] and tandemocracy,[8][note 3] are now used more generally to refer to any system of joint rule or office. A monarchy temporarily controlled by two or more people is, however, usually distinguished as a coregency.
The 2008 Constitution affirms Bhutan's commitment to a traditional dual government sharing power between the Druk Gyalpo ("King") and the Buddhist religious authorities led by the Je Khenpo.[12][13] In practice, however, the religious leaders function more as advisors to the kings than as corulers. Both arms of the traditional dual government are in practice less important than the Parliament and (single) Prime Minister.
The captains regent (Italian: Capitani Reggenti) of San Marino are elected every six months by the Sammarinese parliament, the Grand and General Council. They serve as heads of state and are normally chosen from opposing parties.[15]
The office of king in ancient Sparta was divided between two kings from separate dynasties, each holding a veto over the other's actions. However, the Spartan kings' powers and duties consisted mainly of leading the Spartan army on campaign (during which only one king would usually lead a given force) and certain religious functions, as well as having ex-officio seats in the Gerousia (Senate). Actual day-to-day public administration in Sparta was managed by the ephors.
The Hungarians originally possessed a system of dual kingship, with religious authority vested in the kende and military authority vested in the war-chief (gyula). It is believed that when the kende Kurszán was killed c. 904 a little after the arrival of the Hungarians in Pannonia, his role was usurped by the war-chief Árpád, establishing the Hungarian monarchy. It is not known with certainty whether Árpád was originally the kende or the gyula.
During Japan's shogunate, the emperor was notionally a supreme spiritual and temporal lord who delegated authority for joint rule to the shōgun. In practice, the shōguns' power was so complete that they are usually considered de facto monarchs rather than viceroys or corulers.
Between 1642 and 1751, political power in Tibet was shared between the 5th, 6th, and 7th Dalai Lamas who headed the realm's Buddhist state religion and various secular rulers known as desis. The growing power of the desis caused the 7th Dalai Lama to abolish the post and replace it with a council known as the Kashag, permitting him to consolidate his authority over the realm. A similar system arose in Bhutan, with the Wangchuckgovernor (penlop) of Trongsa becoming the Druk Desi and Druk Gyalpo in 1907. In contrast to Tibet, the dynasty eventually consolidated its power and now rules as the kings of Bhutan.
From 1619-1633, Tsar Michael of Russia ruled along with his father, Patriarch Filaret of Moscow. Both were addressed as Velikiy Gosudar (Great Sovereign), held court together, and when they did not the ceremony was the same. While both were equal in theory, in practice Patriarch Filaret ruled, with Michael supporting whatever his father ordered.[19]
Although the Kingdoms of England, Scotland and Ireland were monarchies, they became de facto diarchies in personal union during the co-rule of William II and III and Mary II. After the Glorious Revolution deposed James VII and II, his kingships were succeeded in 1689 by his daughter Mary and his son-in-law and nephew William, who jointly ruled England, Scotland and Ireland until Mary died in 1694, succeeded by William as the sole monarch.
Under that act, the executive was to be headed by a governor appointed by the Secretary of State, who could consult the Governor General. The governor was responsible to the Secretary of State for acts of omission and commission. He was to maintain law and order in the province and ensure that the provincial administration worked smoothly. In respect of transferred subjects, he was to be assisted by his ministers whereas reserved subjects were to be administered by the Governor General and his executive council.
The members of the Executive Council were to be appointed by the Secretary of State and were responsible to him in all matters. There were certain matters that he was to administer at his own discretion, in which he was responsible to the Secretary of State. Each councillor was to remain in office for a period of four years. Their salaries and service conditions were not subject to the vote of provincial legislature. All decisions in the council were to be taken by a majority of votes, the Governor being able to break ties.
During the establishment of the modern state of Samoa in 1962, power was shared between the two chiefs Malietoa Tanumafili II and Tupua Tamasese Meaʻole. Meaʻole died the next year, after which the country functioned as a monarchy until the death of Tanumafili and a republic thereafter.
Following a coup d'état in 1964, former Vice PresidentRené Barrientos rose to power as president of the military junta. The following year, faced with discontent from loyalists of General Alfredo Ovando Candía, Barrientos promulgated the co-presidency between himself and Ovando Candía. The pair ruled as dual presidents until 1966 when Barrientos resigned in order to run in that year's general election.
Israel
After the 2019–2021 Israeli political crisis, the Israel's Basic Law: The Government underwent a major change. A system of two prime ministers, appointed at the same time by the Knesset, was established. According to the new method, there was an Alternate Prime Minister of Israel in addition to the standard Prime Minister of Israel. After a half of the government's term, the two prime ministers would change positions as part of a rotation government. During the term, the government's roles and duties were divided between the two prime ministers, each one of them entitled to remove ministers without the other's interference.
However, this system did not survive even until the first planned rotation and was abolished again after Benyamin Netanyahu's victory at the end of 2022.
Informal use
Bureaucracy
Shared power arrangements within a modern bureaucracy may also be known as a "diarchy" or "duumvirate". Examples include the joint authority of the Chief of the Defence Force and the Secretary of the Department of Defence over the Australian Defence Organisation.
The status of monarchs is sometimes impugned by accusations of corule when an advisor, family member, lover, or friend appears to have taken too great a hand in government. Lü Buwei in Chinese history and François Leclerc du Tremblay in France are famous examples of "éminences grises" who controlled much of their countries' policies. In British history, George VI's reign was mocked as a "split-level matriarchy in pants" owing to the supposed influence of his mother, Queen Mary and his wife Queen Elizabeth.[20]
Informally shared power
Owing to Confucian notions of filial piety, Chinese and Japanese emperors were sometimes able to 'retire' but continue to exert great influence over state policy. In Indonesia, Sukarno and his vice president Mohammad Hatta were nicknamed the Duumvirate (Dwitunggal), with Sukarno setting government policy and rallying support and Hatta managing day-to-day administration. More recently, the great influence of Vladimir Putin over his successor Dmitry Medvedev was considered a duumvirate,[21] or tandemocracy (see also Medvedev–Putin tandemocracy),[8] until Putin's resumption of the office of president established him as the greater figure.[22]
Within electoral politics, governments, coalitions and parties may sometimes have two fairly equal leaders, as with:
In addition to actual sharing of political power between religious and military leaders, as occurred in Tibet and Bhutan, the great soft power of a religious leader such as the Pope of the Catholic Church over a devout country can sometimes be described as a form of diarchy or corule.
Traditional leaders
The Kingdom of Eswatini is a diarchy in which the King (Ngwenyama) rules in conjunction with his mother, the queen mother (Ndlovukati) in their capacity as traditional rulers. Constitutionally, however, the King is the sole head of state, though it is often argued that the giving of authority wholesale to the royal male in this way is a neo-traditionalistic as opposed to truly traditional custom.[citation needed]
In fiction
In The Gondoliers by Gilbert and Sullivan, the fictional land of Barataria is ruled jointly for a while by two kings, who happen to be the gondoliers themselves.
Umbar, in the works of J. R. R. Tolkien, was ruled by a duumvirate. In its earliest years, Gondor was also ruled jointly by two kings, the two sons of Elendil. He himself was king of its sister realm Arnor, and served as high king over both realms.
The Omaticaya, the Na'vi clan at the center of the film Avatar, are traditionally led by a pair of married tribal chiefs. One of them, the husband, oversees political and military matters while the other one, the wife, is in charge of spiritual and otherwise ceremonial affairs.
The orbital colony New New York, in the Worlds trilogy by Joe Haldeman, is jointly governed by an elected Policy Coordinator and Engineering Coordinator.
The Federated Commonwealths of America, in A Different Flesh by Harry Turtledove, is modelled heavily on the Roman Republic, governed by two chief executives styled as Censors (although the offices are more akin to the position of Consul). With each one being able to veto the actions of the other, the election of two politically-opposed Censors was intended as a check on executive power. Censors serve a single non-renewable five-year term and (alongside commonwealth governors) become life-long-serving members of the Senate upon leaving office.
In My Little Pony: Friendship is Magic, the nation of Equestria where most of the series takes place is shown to be a diarchy. While the older Princess Celestia is depicted as ruling on her own in the first season of the series, she is later joined by her younger sister Princess Luna as a co-ruler.
By the end of Legend of Korra, the Northern Water Tribe becomes a diarchy, ruled by the twins Desna and Eska, cousins to the title character.
^"Why is the President of France Co-Prince of Andorra?". Royal Central. 7 October 2019. Retrieved 9 November 2019. The President of France, Emmanuel Macron, serves as Co-Prince of Andorra in addition to his duties as French President and is one of the few examples of a democratically elected leader serving in a royal capacity in another country. Since 2003, the other Co-Prince is the Catholic Bishop of Urgell from Spain, Joan-Enric Vives i Sicília.