Diarchy (from Greek , di-, "double", and , -arkhía, "ruled"), duarchy, or duumvirate (from Latin , "the office of the two men") 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. Historically, diarchy particularly referred to the system of shared rule in British India 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. Both, along with less common synonyms such as biarchy and tandemocracy, 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. Corule is one of the oldest forms of government. Historical examples include the Pandyan dynasty of Tamilakam, Sparta's joint kingship, the Roman Republic's consuls, Carthage's Judges, and several ancient Polynesian societies. Systems of inheritance that often led to corule in Germanic and Dacian monarchies may be included as well, as may the dual occupants of the ranks of the Inca Empire. Modern examples of diarchies are Andorra, whose princes are the President of France and the Bishop of Urgell in Catalonia; and San Marino, whose republic is led by two Captains Regent. Formal use Current diarchies Andorra Andorra is a parliamentary co-principality. Its princes are (ex officio) the French president and the bishop of Urgell in Catalonia, Spain. Since 1962, the French president has been elected by universal suffrage within France. The bishop of the diocese of Urgell is appointed by the Roman Catholic pope. Bhutan 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. In practice, however, the religious leaders function more as advisors to the kings than as corulers. Northern Ireland Under the terms of the 1998 Good Friday Agreement intended to end conflict in Northern Ireland, the First Minister and deputy First Minister serve as joint heads of the area's executive. Both positions exercise identical executive powers; however they are not heads of state. San Marino The captains regent () of San