Vonones I was an Arsacid prince, who ruled as King of Kings of Parthian Empire from 8 to 12, and subsequently as king of Armenia from 12 to 18. He was the eldest son of Phraates IV and was sent to Rome as a hostage in 10/9 BC in order to prevent conflict over the succession of Phraates IV's youngest son, Phraataces.

Phraates IV was King of Kings of the Parthian Empire from 37 to 2 BC. He was the son and successor of Orodes II, 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.