Parthia, Phraates IV 38/7-2 BC, Tetradrachm, 10.30g.

Phraates IV (also spelled Frahad IV; Parthian: 𐭐𐭓𐭇𐭕 Frahāt) was King of Kings of the Parthian Empire from 37 to 2 BC. He was the son and successor of Orodes II (r. 57–37 BC), and was given the throne after the death of his brother Pacorus I. Phraates IV soon murdered all his brothers, and also possibly his father. His actions alienated the Armenians and also some of his nobles, including the distinguished Monaeses, who fled to the Roman triumvir Mark Antony, but shortly returned and reconciled with Phraates IV.

Phraates IV was attacked in 36 BC by Mark Antony, who marched through Armenia into Media Atropatene, and was defeated and lost the greater part of his army. Antony, believing himself betrayed by Artavasdes II, king of Armenia, invaded his kingdom in 34 BC, took him prisoner, and concluded a treaty with Artavasdes I, king of Media Atropatene. But when the war with Octavian broke out, Antony could not maintain his conquests; Phraates IV recovered Media Atropatene and made Artaxias, the son of Artavasdes II, king of Armenia.