Triumvir
Triumvir , noun
[Latin, from res, gen. trium, three + vir a man. See Three, and Virile.]
(Rom. Antiquities) One of tree men united in public office or authority.
In later times the triumvirs of Rome were three men who jointly exercised sovereign power. Julius Caesar, Crassus, and Pompey were the first triumvirs; Octavianus (Augustus), Antony, and Lepidus were the second and last.