 Catholic communities were already established in Greece since the 13th century ( Athens , Cyclades , Chios , Crete ) . Jewish communities also existed in the country , those arriving after the Expulsion of the Jews from Spain ( 1492 ) joining the earlier Romaniotes , Jews who had been living there since the times of Apostle Paul . Muslim families were still living in Greece during Otto 's reign , since hostility was mainly against the Ottoman state and its depressive mechanisms and not against Muslim people . 
