Pacorus I of Parthia

Pacorus I
Prince of the Parthian Empire
Coin of Pacorus I, with Inscription of Parthian imperial power.
Born	63 BC
Died	38 BC Cyrrhestica
Spouse	Unnamed Artaxiad princess
House	Parthian dynasty
Father	Orodes II
Mother	Laodice
Religion	Zoroastrianism

Pacorus I (died 38 BC) was a Parthian prince, who was the son of King Orodes II and Queen Laodice. It is possible that Pacorus was co-ruler with his father for at least part of his father's reign. His wife was an unnamed Armenian princess, who was one of the daughters of King Tigranes the Great of Armenia and his wife, Queen Cleopatra of Pontus.

Pacorus is first mentioned in 51 BC, then probably about 12 years old, as the head of a Parthian army during an invasion of the Roman province of Syria. However, because of the young age of Pacorus, the Parthian operations were probably led by the Parthian commander Osakes. According to the Roman historian Cassius Dio, the Parthian army besieged Antioch, but were unable to capture the city and withdrew. During this event, Osakes was killed during a Roman counter-attack under the Roman general Gaius Cassius Longinus, which made the Parthian troops under Pacorus retreat back to their homeland.

Some time later, when the Roman consul Marcus Calpurnius Bibulus, was appointed the governor of Syria, tried to incite the Parthians against each other; he had close friendship with a Parthian satrap who harbored a grudge against king Orodes II, and made him crown the young Pacorus as rival-king of the Parthian Empire and made a campaign against Orodes. Even coins with the portrait of Pacorus were briefly minted. However, Pacorus and his father reconciled to each other and coins with the portrait of Pacorus were stopped minting. The Parthian satrap who was behind the plot was probably shortly executed.

In 42 BC, Quintus Labienus, a Roman rebel, began serving the Parthians. Later in 40 BC, the Parthians under Pacorus and Labienus invaded the Roman territories. The Parthian army crossed the Euphrates and attacked Apamea. The attack on Apamea failed but Labienus was able to entice the Roman garrisons around Syria to rally to his cause. The combined Romano-Parthian army then proceeded to defeat Mark Antony's governor L. Decidius Saxa in a pitched battle and took Apamea. After the Roman defeat at Apamea, the Parthians split their army. Pacorus turned south and conquered the Levant from the Phoenician coast through Palestine. Labienus turned north to follow Saxa, whom he defeated and killed in Cilicia. In Judea, Pacorus' deputy Barzapharnes deposed king Hyrcanus II and appointed the latter's nephew Antigonus as king in his place.