Triumvirate, try UHM vuhr iht, in the history of ancient Rome, was a group of three men who attempted to seize control of the government. Rome had two triumvirates. The first, formed about 60 B.C., was made up of Julius Caesar, Pompey the Great, and Marcus Licinius Crassus. The second was formed in 43 B.C., after Brutus and Cassius had murdered Caesar. Its members were Octavian (Augustus), Marcus Lepidus, and Mark Antony.