While he and his sister were growing up in Rome, they were part of the remarkable court of Antonia Minor, a niece of the first Roman emperor Augustus and the youngest daughter of the triumvir Mark Antony.

[2][3] The reasons for providing a client king with such vast resources remain unclear; it was perhaps a stroke of Caligula's well-attested eccentricity.

Antiochus was on most intimate terms with Caligula, and he and King Agrippa I are spoken of as the instructors of the emperor in the art of tyranny.

[7] In 55 he received orders from the Roman emperor Nero to levy troops to make war against the Parthians, and in the year 59 he served under General Cn.

[13] Antiochus' downfall came only two years afterwards, in 72, when he was accused by L. Caesennius Paetus, the governor of Syria, of conspiring with the Parthians against the Romans.

Antiochus himself retired first to Sparta and then to Rome, where he passed the remainder of his life with his sons Epiphanes and Callinicus and was treated with great respect.

There are several coins of this king extant, and their die-marks prove he did rule large parts of Cappadocia and Cilicia as well as Commagene proper.

In one of those coins he is called ΒΑΣΙΛΕΥΣ ΜΕΓΑΣ ΑΝΤΙΟΧΟΣ ("Great King Antiochus"), a testament to his political ambitions.