A triumvirate (Latin: triumvirātus) is a political regime ruled or dominated by three powerful individuals known as triumvirs (Latin: triumviri). The arrangement can be formal or informal. Though the three are notionally equal, this is rarely the case in reality. The term can also be used to describe a state with three different military leaders who all claim to be the sole leader.
In the context of the Soviet Union and Russia, the term troika (Russian for "group of three") is used for "triumvirate". Another synonym is triarchy.
Originally, triumviri were special commissions of three men appointed for specific administrative tasks apart from the regular duties of Roman magistrates. The triumviri capitales, for instance, oversaw prisons and executions, along with other functions that, as Andrew Lintott notes, show them to have been "a mixture of police superintendents and justices of the peace." The capitales were first established around 290–287 BCE. They were supervised by the praetor urbanus. These triumviri, or the tresviri nocturni, may also have taken some responsibility for fire control.  The triumviri monetalis ("triumviri of the temple of Juno the Advisor" or "monetary triumvirs") supervised the issuing of Roman coins.
Three-man commissions were also appointed for purposes such as establishing colonies (triumviri coloniae deducendae) or distributing land.Triumviri mensarii served as public bankers; the full range of their financial functions in 216 BCE, when the commission included two men of consular rank, has been the subject of debate. Another form of three-man commission was the tresviri epulones, who were in charge of organizing public feasts on holidays. This commission was created in 196 BCE by a tribunician law on behalf of the people, and their number was later increased to seven (septemviri epulones).
Despite the Three Excellencies—including the Chancellor, Imperial Secretary, and irregularly the Grand Commandant—representing the most senior ministerial positions of state, this triumvirate was supported by the economic technocrat and Imperial Secretary Sang Hongyang (d. 80 BCE), their political lackey. The acting Chancellor Tian Qianqiu was also easily swayed by the decisions of the triumvirate.
The Three Excellencies existed in Western Han (202 BCE – 9 CE) as the Chancellor, Imperial Secretary, and Grand Commandant, but the Chancellor was viewed as senior to the Imperial Secretary while the post of Grand Commandant was vacant for most of the dynasty. After Emperor Guangwu established the Eastern Han (25–220 CE), the Grand Commandant was made a permanent official while the Minister over the Masses replaced the Chancellor and the Minister of Works replaced the Imperial Secretary. Unlike the three high officials in Western Han when the Chancellor was senior to all, these new three senior officials had equal censorial and advisory powers. When a young or weak-minded emperor ascended to the throne, these Three Excellencies could dominate the affairs of state. There were also other types of triumvirates during the Eastern Han; for example, at the onset of the reign of Emperor Ling of Han (r. 168–189), the General-in-Chief Dou Wu (d. 168), the Grand Tutor Chen Fan (d. 168), and another prominent statesman Hu Guang (91–172) formed a triumvirate nominally in charge of the Privy Secretariat, when in fact it was a regent triumvirate that was overseeing the affairs of state and Emperor Ling.
In Hinduism, the gods Brahma, Vishnu and Shiva form the triumvirate Trimurti "in which the cosmic functions of creation, maintenance, and destruction are personified" respectively by those gods.."
Prior to Napoleon and during the Terror Robespierre, Louis de Saint-Just, and Couthon, as members of the governing Committee of Public Safety, were purported by some to have formed an unofficial triumvirate. Although officially all members of the committee shared equal power the three men's friendship and close ideological base led their detractors to declaim them as triumvirs which was used against them in the coup of 9 Thermidor.
2012: The leadership of Shas, the ultra-orthodox Sepharadi political party of Israel, was given by its spiritual leader, Rabbi Ovadia Yosef and the Council of Torah Sages, to a triumvirate formed by the convicted Aryeh Deri, who decided to return to politics after a thirteen-year hiatus, the former party leader Eli Yishai and Ariel Atias.
People's Republic of China
(L-R) Zhou Enlai, Mao Zedong, and Liu Shaoqi in 1964
May 1922 – April 1925: When Vladimir Lenin suffered his first stroke in May 1922, a Troika was established to govern the country in his place, although Lenin briefly returned to the leadership from 2 October 1922 until a severe stroke on 9 March 1923 ended Lenin's political career. The Troika consisted of Lev Kamenev, Joseph Stalin, and Grigory Zinoviev. The Troika broke up in April 1925, when Kamenev and Zinoviev found themselves in a minority over their belief that socialism could only be achieved internationally. Zinoviev and Kamenev joined forces with Leon Trotsky's Left Opposition in early 1926. Later, Kamenev, Zinoviev and Trotsky would all be murdered on Stalin's orders.
1–4 July 1849: Aurelio Saffi (again), Alessandro Calandrelli (b. 1805 – d. 1888), and Livio Mariani (no dates available)
After the downfall of the first King of Greece, the Bavarian Otto, on 23 October 1862, and Dimitrios Voulgaris' unsuccessful term (23 October 1862 – 30 January 1863) as president of the Provisional Government, a Triumvirate (30 January – 30 October 1863) was established consisting of the same Dimitrios Voulgaris, the renowned Admiral Konstantinos Kanaris and Benizelos Rouphos, which acted as a regency until the arrival of the new monarch, the first "King of the Hellenes", George I.
A triumvirate was established to head the Theriso revolt of 1905 in autonomous Crete, consisting of Eleftherios Venizelos (later Prime Minister of Greece) in charge of organisational matters, Konstantinos Foumis in charge of finances and Konstantinos Manos, the former mayor of Chania, in charge of military affairs.
The "Triumvirate of National Defence": (L-R) Admiral Kountouriotis, Venizelos, and General Danglis
A triumvirate was set up on 13 September 1922 to lead the military revolt against the royalist government in Athens in the aftermath of the Asia Minor Disaster. It was composed of Colonels Nikolaos Plastiras and Stylianos Gonatas, and Commander Dimitrios Fokas. The triumvirate assumed the government of Greece on 15 September, and would control the country until it laid down its powers on 2 January 1924. Plastiras however quickly became the dominant figure among the triumvirate, and was eventually labelled as the "Chief of the Revolution".
Eric Schmidt, CEO of Google has referred to himself, along with founders Larry Page and Sergey Brin as part of a triumvirate, stating, "This triumvirate has made an informal deal to stick together for at least 20 years".
The word has been used as a term of convenience, though not an official title, for other groups of three in a similar position:
^Triumviri or tresviri nocturni may be another name or nickname for the capitales, because their duties often pertained to the streets at night.
^John E. Stambaugh, The Ancient Roman City (Johns Hopkins University Press, 1988), p. 347, note 4 online and p. 348, note 13; O.F. Robinson, Ancient Rome: City Planning and Administration (Routledge, 1994), p. 105 online.
^Andrew Lintott, The Constitution of the Roman Republic (Oxford University Press, 1999), pp. 12 and 95 online.
^Jean Andreau, Banking and Business in the Roman World (Cambridge University Press, 1999), p. 115 online.
^Rachel Feig Vishnia, State, Society, and Popular Leaders in Mid-Republican Rome, 241-167 B.C. (Routledge, 1996), p. 86ff. online.
^Livy 33.42.1; Vishnia, State, Society, and Popular Leaders, p. 171; Fergus Millar, Rome, the Greek World, and the East (University of North Caroline Press, 2002), p. 122 online; Lintott, Constitution, p. 184.
Beck, Mansvelt. (1986). "The Fall of Han," in The Cambridge History of China: Volume I: the Ch'in and Han Empires, 221 B.C. – A.D. 220. Edited by Denis Twitchett and Michael Loewe. Cambridge: Cambridge University Press. ISBN0-521-24327-0.
Flood, Gavin (Editor) (2003). The Blackwell Companion to Hinduism. Malden, MA: Blackwell Publishing Ltd. ISBN1-4051-3251-5.CS1 maint: extra text: authors list (link)
Loewe, Michael. (1986). "The Former Han Dynasty," in The Cambridge History of China: Volume I: the Ch'in and Han Empires, 221 B.C. – A.D. 220, 103–222. Edited by Denis Twitchett and Michael Loewe. Cambridge: Cambridge University Press. ISBN0-521-24327-0.