Helena Kantakouzene, Empress of Trebizond  Helena Kantakouzene (died 1463) was the second wife of David of Trebizond, the last Emperor of Trebizond. Recent research has led to doubts regarding her existence. Donald Nicol has argued that Helena was the sister of George Palaiologos Kantakouzenos, and thus the granddaughter of Matthew Kantakouzenos and possibly the daughter of Theodore Kantakouzenos. Theodore Spandounes reports that George visited her in Trebizond after 1437. It is unclear which of David's children were also hers; his five children—three boys and two daughters—have been attributed variously to Helena or David's first wife Maria of Gothia by various genealogies. Nevertheless, the oldest sons died with their father 1 November 1463; the youngest son, George, who was three years old, and the daughter Anna were spared. 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. Spandounes says the name of the king who sheltered George Kantakouzene and gave him his daughter in marriage was named "Gurguiabei", which has been interpreted as a king of Georgia (and either George VIII or Constantine II), or "Guria Bey", ruler of Guria. Anna's fate is less clear. The historian Laonikos Chalkokondyles contradicts Spandounes, writing that after being "summoned to his bedchamber", Anna was married to Zagan Pasha; however, when he learned Zagan attempted to force her to become a Muslim, Mehmet separated them. A local tradition connects Anna to a village south of Trabizon called "Lady Village", where in 1870 an inscription bearing Anna's name was seen in the village church dedicated to the Archangels. On 15 August 1461, Mehmed II of the Ottoman Empire forced Emperor David to surrender his throne in return for a pension. David and his family were settled on estates near Serres in the Struma valley, comprising an annual income of some 300,000 pieces of silver. 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. After two years, his former retainer George Amiroutzes accused David of conspiring against Mehmed, and the former emperor was executed with all but one of his sons.