After giving up soldiering in 1525, Theodore served as a diplomat and translator, and since he could speak Italian, Greek and Turkish, he accompanied Venetian ambassadors to the Ottoman Empire several times.

Theodore had three siblings; Georgios (Giorgio or Zorzi in Italian), Matthew (who would become the abbot of a monastery on Zakynthos) and a sister whose name remains unknown.

[2] In his youth, Theodore originally worked as a soubashi (debt-collector/police enforcer) in the Peloponnese on behalf of the Ottoman Empire, which conquered the Morea in 1460, before he, his father,[1] and his brother Georgios,[2] took up service with the Republic of Venice as stratioti (light-armed mercenary cavalrymen)[1][3] in 1478.

[2] One of the earliest preserved references to Theodore is a 1479 decision by the Venetian Senate concerning him, which states that he had recently proven himself in battle on a campaign in Friuli.

[2] In 1483, Theodore and his brother Georgios were appointed as military governors on the Venetian-held Greek island of Zakynthos, being granted grand properties and salaries.

In addition to Greek and Italian, he also spoke Ottoman Turkish, and he frequently accompanied Venetian ambassadors and other officials on their visits to the eastern Mediterranean.

Because they could speak Turkish, Theodore and his nephew Costantino (son of his brother Georgios) served as dragomani (translators/interpreters) for Ottoman dignitaries visiting Venice.

[4] Theodore had prior knowledge of diplomacy, having accompanied the Venetian ambassador Alvise Maneti to the Ottoman court in Adrianople in March 1500.

[1] On account of his years of military service and his work as a diplomat and translator, the Venetian government awarded Theodore with their highest honor; bestowing upon him a Knighthood of Saint Mark.

His coffin was carried by a guard of honor of mariners to the temporary structures on the site were the city's Greek Orthodox church, San Giorgio dei Greci, was being built.