Helena Kantakouzene, Empress of Trebizond

Spandounes states they were sent as a present to Sultan Uzun Hassan of the Aq Qoyunlu, where George was converted to Islam, but he eventually escaped and abjured to Christianity.

Although Helena presumably was with him, Donald Nicol mentions a source which states David had sent her to refuge with the Georgian prince Mamia of Guria prior to Mehmed's arrival before the walls of Trebizond.

Her retainers raised the money, but Helena dressed in sackcloth and lived out her days in a straw hut near the corpses of her dead family.

Ganchou refers to the historical writings of Angelo Massarelli, the Papal Secretary to the Council of Trent,[9][a] which state that Theodora was the daughter of Theodore Kantakouzenos.

This identification is also reinforced by the historian George Sphrantzes, who refers to Theodora's other son John IV as a cousin to Mara Branković, herself a granddaughter of Theodore.

[b] It may be that he had assumed that the emperor in question was the final ruler of the kingdom and then, given that the name Helena appears frequently among the Kantakouzenos, assigned it to the unnamed wife.