Are you denying that Greece was part of the Ottoman Empire for several centuries?
Greece was invaded and existed as a subjugated enslaved millet of the Muslim Ottoman Turks for about 400 years.
Being Christian, most Greeks quietly and secretly held fast to their faith while suffering the worst atrocities imaginable by any oppressed people. Unfortunately they could not save their fellow Christians in Asia Minor who were mostly exterminated by the end of the 20th century.