A triumvirate (triumvirātus) or a triarchy is a political institution ruled or dominated by three individuals, known as triumvirs (triumviri). The arrangement can be formal or informal. Though the three leaders in a triumvirate are notionally equal, the actual distribution of power may vary. 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 Bible triumvirates occurred at some notable events in both the Old Testament and New Testament. In the Book of Exodus Moses, his brother Aaron and, according to some views their nephew or brother-in-law, Hur acted this way during the Battle of Rephidim against the Amalekites. Later, when Moses was away on the Mount Sinai Aaron and Hur were left in charge of all the Israelites.
In the Gospels as a leading trio among the Twelve Apostles at three particular occasions during public ministry of Jesus acted Peter, James, son of Zebedee and his brother John. They were the only apostles present at the Raising of Jairus' daughter, Transfiguration of Jesus and Agony in the Garden of Gethsemane. Later, at the time of the Early Christian Church this triumvirate of the leading apostles changed slightly after the former James's death, as it became composed of Peter, John and James, brother of Jesus, known collectively also as the three Pillars of the Church.
During the Han Dynasty (202 BCE – 220 CE), statesmen Huo Guang (d. 68 BCE), Jin Midi (d. 86 BCE), and Shangguan Jie 上官桀 (d. 80 BCE) formed a triumvirate following the death of Emperor Wu of Han (r. 141–87 BCE) and the installation of the child emperor Zhao.
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.