Joan was daughter of Philip I, Prince of Taranto, and his first wife Thamar Angelina Komnene.
[1] Joan's parents did not have a good relationship: Philip suspected Thamar of acting in her family's interests over his during the two-year conflict that raged between the Capetian House of Anjou and Epirus, despite the fact that she had pawned the remainder of her jewellery to help him pay for the military effort.
Shortly following her mother's death, Joan acquired a stepmother in Catherine of Valois, who Philip married in July 1313.
From this marriage Joan acquired five half-siblings, including Philip II, Prince of Taranto.
Joan's husband and brother-in-law Constantine, Constable of Armenia and Lord of Lampron, and Leo's wife Alice were all murdered on the king's orders, the head of Oshin being sent to the Ilkhan and of Constantine to Al-Nasr Muhammad.