He was born to a distinguished and pious Christian family in Thessalonika. After acquiring an unusually good education he spent a few years in Constantinople, then returned to his native city. He spoke both Turkish and Arabic well, and often conversed with Muslims. Once, while speaking with an emir, Athanasius pronounced the Muslim confession of faith to illustrate a point. The emir, seeing an opportunity, immediately reported Athanasius to the Islamic judge, claiming that he had converted to Islam. The judge found no merit in the case and would have dismissed Athanasius; but the emir and other officials were insistent, and the judge pressured Athanasius to convert. When Athanasius answered that he knew no truth but that of Christ, he was thrown in prison. When he appeared before the judge several days later, he was still firm in his confession, and was sentenced to death. He was hanged outside the city in 1774, at the age of twenty-five.