[1] His father was a Greek soldier who entered the service of the Venetian Republic as a stradioti mercenary, and for unspecified exploits was made a count of the Holy Roman Empire and imperial knight by Emperor Frederick III in 1454.
This was a nominal grant meant as a gesture of honour, since the territory in question was under Ottoman control, but according to historian Donald Nicol it is possibly indicative of Matthew's and his family's place of origin.
[1] On the other hand, both Spandounes and other members of the family still remaining in the Ottoman-ruled Balkans claimed descent from Constantinople itself, while some had settled in Venice as early as the 1370s.
[2] Theodore's mother was a descendant of the Kantakouzenoi, one of the most notable late Byzantine aristocratic lines, which had produced a number of emperors as well as rulers of the Despotate of the Morea in the Peloponnese.
After Murad's death in 1451, Mara was allowed by her stepson Sultan Mehmed II, to retire to her estate at Ježevo, where she "maintained a privileged and protected enclave of Christian faith" (Nicol).
[11] Although he remained an Orthodox Christian, Spandounes turned to the Roman Catholic Church for aid, and served as advisor and confidante to several Popes who would champion his cause, starting with Leo X (1513–21), for whom he prepared the second draft of his work in 1519.
He fell out with Leo's successor, Pope Hadrian VI, who not only showed no interest in the war against the Turks, but also cut his family's pension, but resumed his position under Clement VII (1523–34) and Paul III (1534–49).
Likewise there is little to suggest that he knew and made use of the handful of Italian treatises on the Turks that were written at about the same time, except for the works of Marin Barleti, whom Spandounes mentions by name.