Eunia, sometimes known as Ennia, was a Greek woman who lived in the 1st century Roman Empire. According to Suetonius she is known as Ennia Naeva (Greek: η Ευνία).
Eunia was of Greek and Armenian descent. She was the daughter and second child born to Egyptian Greek Thrasyllus of Mendes or Tiberius Claudius Thrasyllus and a Greek princess from the Kingdom of Commagene, Aka II of Commagene, who was either a granddaughter or great-granddaughter of King Antiochus I Theos of Commagene. Her father, an Alexandrian grammarian and editor of Plato and Democritus, was a noted astrologer, who became a friend to the future Roman Emperor Tiberius.
Her eldest brother was Tiberius Claudius Balbilus, who became a learned scholar, a Roman magistrate and later prefect of Egypt. Her niece was Claudia Capitolina who would marry into the Kingdom of Commagene. Eunia and her brother were most probably born and raised in their father’s house in Alexandria, Egypt.
Eunia married the Praetorian Prefect Naevius Sutorius Macro. After the downfall and death of the Praetorian Prefect Lucius Aelius Sejanus in Rome in 31, her husband was appointed by the then Roman Emperor Tiberius to replace the former. Macro’s new position gave considerable influence to both Eunia and himself.
Macro and Eunia came into favor with Tiberius’ great-nephew and heir, Caligula. According to Suetonius, Caligula seduced Eunia. Tacitus states that Macro induced Eunia to pretend to love Caligula.
After Eunia and Caligula’s affair in Capri in 34, Caligula swore to marry Eunia if he became Emperor, putting this oath in writing. The interaction between Macro, Eunia and Caligula assisted Caligula in succeeding Tiberius when the latter died in 37. Sometime in 38 Eunia and Macro fell out of favor with Caligula and they both committed suicide.
Note these articles are partly based from the information of articles Thrasyllus of Mendes and Naevius Sutorius Macro from Wikipedia.