Demetrios Kydones

Demetrios Kydones (1324–1398) was a Byzantine theologian, translator and statesman born in Thessalonica who served an unprecedented three terms as mesazon, the empire's chief minister, under John VI Kantakouzenos from 1347, John V Palaiologos from 1369 to 1383 and Manuel II. Learning Latin at John VI's request, he translated Thomas Aquinas' Summa contra Gentiles and Summa Theologica into Greek, introducing Latin scholasticism to Byzantine readers.

A Catholic by 1365, he sought reconciliation between the Eastern and Western churches to secure a military alliance. In 1369 he accompanied John V to Rome to seek papal support against the Ottoman Turks.