His paternal grandfather Alexander was a Judean prince of Jewish, Nabataean and Edomite descent and was a son of King of Judea, Herod the Great and his wife Mariamne.

She was the daughter of King Archelaus of Cappadocia[5] and her mother was an unnamed princess from Armenia,[6] possibly a relation of the Artaxiad dynasty.

Nero had given to Tigranes a guard of 1000 legionary soldiers, three auxiliary cohorts and two wings of horses were allotted to him in order to defend and protect Armenia.

At the same time, his son Alexander married Julia Iotapa a Commagenean princess and the daughter of King Antiochus IV of Commagene in Rome.

Nero crowned Alexander and Iotapa as Roman client monarchs of Cetis, a small region in Cilicia, which was previously ruled by Antiochus IV.

Tigranes invaded a neighbouring small vassal state of the Parthians called Adiabene and deposed their King Monobazes.

Eventually, the Parthians signed a treaty with Corbulo to install Tiridates I as King of Armenia as long as he goes to Rome to be crowned by Nero.

[12] There are three princes by the name Phasael in the Herodian dynasty, all three mentioned by Josephus in "War" (BJ) and "Antiquities" (AJ):[13]