Antony ' s Parthian War Antony ' s Parthian War or the Roman - Parthian War of 40 - 33 BC was a major conflict between the Roman Republic , represented in the East by the triumvir Mark Antony , and the Parthians . Although the campaign ended in distastrous defeat for Antony , the war became a strategic draw when peace was later negotiated by Augustus . Background . Julius Caesar , after ensuring victory in his civil war , planned a campaign into the Parthian Empire in 44 B . C . to avenge the earlier defeat of a Roman army led by Marcus Crassus at the Battle of Carrhae . Caesar ' s plan was , after a brief pacification of Dacia , to continue east into Parthian territory . After his assassination , the Second Triumvirate , composed of Marcus Antonius ( Antony ) , Marcus Lepidus and Gaius Octavianus ( later known as Augustus ) . After the defeat of Caesar ' s assassins at the Battle of Philippi , Caesarian rule over the Republic was effectively ensured . Shortly after , however , with the triumvirs preoccupied with the revolt of Sextus Pompeius in Sicily , Parthia attacked Roman - controlled Syria and the client kingdom of Judea . The Judean high priest and puppet Roman ruler , Hyrcanus II , was overthrown and sent as prisoner to Seleucia , and the pro - Parthian Hasmonean Antigonus was installed in his place . Antigonus was the only remaining son of former king Aristobulus II who the Romans deposed when they installed the weaker Hyrcanus II as high priest ( but not king ) in 63 BC . Upon capturing Hyrcanus II , Antigonus bit off his uncle ' s ears to disqualify him from ever again serving as high priest . In Anatolia , the Parthians allied with Quintus Labienus , son of Caesar ' s former general and later antagonist Titus Labienus , penetrating deep into the west and defeating a Roman army under Decidius Saxa . They were however defeated in turn by a veteran army led by Publius Ventidius Bassus , who drove the invaders from Roman territory . The war . With the aid of Mark Antony , Triumvir and lover of Egyptian Ptolemaic Queen Cleopatra VII , the son - in - law of Hyrcanus , Herod , returned to Judea and recaptured Jerusalem in 37 BC . Antony then went on to attack the Parthian Empire itself , marching into Atropatene ( present - day Iranian Azerbaijan ) with some 100 , 000 legion aries , aided by the Roman client kings in Armenia , Galatia , Cappadocia and sovereign Pontus . The campaign proved a disaster however , after a Roman slipup at Phraaspa , capital of Atropatene , and thousands of Romans and auxiliaries died during the retreat due to the cold winter . Antony lost more than a quarter of its strength in the course of the campaign . Again with Egyptian money , Antony invaded Armenia , this time successfully . In the return , a mock Roman Triumph was celebrated in the streets of Alexandria . The parade through the city was a pastiche of Rome ' s most important military celebration . For the finale , the whole city was summoned to hear a very important political statement . In 34 BC , surrounded by Cleopatra and her children , Antony ended his alliance with Octavian . Subsequent events . Antony later went on to annex Armenia , afraid the kingdom would seek Parthian support , but the war didn ' t end formally until 20 BC , by a peace made by Augustus , ensuring the return of the captured legionary eagles of Crassus ' and Saxa ' s armies , Antony ' s main excuse for the invasion of Parthia proper .