Quintus Labienus Parthicus was a Roman general in the Late Republic period. The son of Titus Labienus, he made an alliance with Parthia and invaded the Roman provinces in the eastern Mediterranean which were under the control of Mark Antony. He occupied the Roman province of Syria together with the Parthians in 40 BC. He then pushed into southern Anatolia, still with Parthian support. The main Parthian force took charge of Syria and invaded Judea. Both Labienus and the Parthians were defeated by Publius Ventidius Bassus, who recovered these provinces for Mark Antony.

The Second Triumvirate was an extraordinary commission and magistracy created for Mark Antony, Lepidus, and Octavian to give them practically absolute power. It was formally constituted by law on 27 November 43 BC with a term of five years; it was renewed in 37 BC for another five years before expiring in 32 BC. Constituted by the lex Titia, the triumvirs were given broad powers to make or repeal legislation, issue judicial punishments without due process or right of appeal, and appoint all other magistrates. The triumvirs also split the Roman world into three sets of provinces.