Iotapa and her brother appeared to be very young, when their father died in 17. Roman Emperor Tiberius agreed with the citizens of Commagene to make their Kingdom apart of the Roman province of Syria. From 17 until 38, Iotapa seems that she had gain Roman citizenship. Iotapa would have put the Latin name Julia, as apart of her name. She had lived and was raised in Rome, along with her brother. While Iotapa and Antiochus were growing up in Rome, they were apart of the remarkable court of Antonia Minor. Antonia Minor was a niece of the first Roman Emperor Augustus and the youngest daughter of triumvir Mark Antony. Antonia Minor was a very influential woman and supervised her circle of various princes and princesses. Her circle assisted in the political preservation of the Roman Empire’s borders and affairs of the client states.
The Roman Emperor Caligula returned to her and Antiochus IV their paternal dominion in 38. In addition, the emperor even enlarged their territory with apart of Cilicia bordering on the seacoast. Caligula also gave them one million gold pieces the whole amount of the revenues of Commagene during the twenty years that it had been under a Roman province. The reasons for providing a client kingdom with such vast resources remain unclear; it was perhaps a stroke of Caligula's well-attested eccentricity.
Iotapa had married her brother and became Roman Client Monarchs of Commagene. Iotapa and Antiochus IV had three children:
On coinage her royal title is ‘Queen Iotape Philadelphus’ or ‘ΒΑΣΙΛΙΣΣΑ ΙΩΤΑΠΗ ΦΙΛΑΔΕΛΦΟΣ’. The title Philadelphus reveals to us that she is the sister-wife of Antiochus IV. This also shows her descent and claim to the Royal Cult that was established by her late ancestor Antiochus I.
She was of Armenian, Greek and Medes descent. Through her ancestor from Commagene, Queen Laodice VII Thea, who was the mother of King Antiochus I Theos of Commagene, she was a direct descendant of the Greek Syrian Kingdom the Seleucid Empire. She was most probably born, raised and educated in Samosata, the capital of the Kingdom of Commagene. Her mother died around 52 and her father raised her.
Iotapa’s father Antiochus IV, was an ally to the Roman Emperor Nero and various members of the Herodian Dynasty. Between 58-59, there was civil unrest and warfare that occurred in the Kingdom of Armenia. Majority of Armenians had abandoned resistance and wanted peace, which included in accepting a prince to be crowned by Nero to be an Armenian King. Antiochus IV had participated in protecting Armenia with the Romans from Tiridates I of Armenia.
Nero crowned as the new Armenian King in Rome a prince called Julius Tigranes, who was of Jewish, Armenian, Nabataean and Edomite origin. Tigranes was the son of Judean prince Alexander. Tigranes was the grandchild of Cappadocian Princess Glaphyra and prince Alexander of Judea. His great grandparents were King Archelaus of Cappadocia, King of Judea Herod the Great and Queen Mariamne I.
Tigranes from his marriage had a son called Gaius Julius Alexander. After Tigranes was crowned King in Rome, his son Alexander had married Iotapa in Rome. The marriage between Alexander and Iotapa was mostly a political alliance that occurred between the fathers of Iotapa and Alexander.
After the marriage of Iotapa and Alexander occurred in Rome, Nero crowned them Queen and King of Cetis, a small distinct in Cilicia, that was previously ruled by her father and her royal ancestors from Commagene. The Roman city in Cilicia Elaiussa Sebaste was made apart of their Kingdom. Iotapa and Alexander ruled Cetis from 58 until at least 72. Iotapa was still alive when the Flavian dynasty had ruled the Roman Empire from 69-96. However after that, there is no more known on Iotapa.
Iotapa bore Alexander two sons who were: Gaius Julius Agrippa and Gaius Julius Alexander Berenicianus. The children of Iotapa and Alexander were both born and raised in Cetis. A possible descendant of this Iotapa, was the usurper Jotapianus, who lived in the 3rd century.
Her paternal grandparents are unknown however; her paternal uncle was the late Emesan King Gaius Julius Azizus. Her maternal grandparents were Queen Julia Urania and King Ptolemy of Mauretania. Julia Urania most probably came from this Royal Family. Ptolemy of Mauretania was the son of African Queen Cleopatra Selene II (daughter of Ptolemaic Greek Queen Cleopatra VII of Egypt and Roman Triumvir Mark Antony) and African King Juba II (son of African King Juba I of Numidia). Little is known on her life. Syrian Queen of Palmyra, Zenobia is descended either from her or her brother.