When young he was captured in his native town of Asculum (which had joined the Social War, the revolt of the Italian socii, or allies, from Rome) by Pompeius Strabo, in whose triumphal procession he was led in 89 B.C. Though derided by ancient writers as a "muleteer," he was probably an army contractor.
Later he won the support of Julius Caesar, with whose help he entered the Senate. After Caesar's death, as praetor in 43, he raised three legions in Picenum and went to help Mark Antony after his defeat at Mutina. He was rewarded by being made consul suffectus (43).
Sent later by Antony to expel the invading Parthians from Asia Minor and Syria, he defeated them near the Taurus Mountains and at Mt. Amanus in 39, and at Mt. Gindarus in 38. He died soon after celebrating his Parthian triumph in 38 and received a public funeral.