Halki seminary
 The Halki seminary formally the Theological School of Halki (Greek: Θεολογική Σχολή Χάλκης) was founded on 1 October 1844 on the island of Halki (Turkish: Heybeliada) the second-largest of the Princes' Islands in the Sea of Marmara. It was the main school of theology of the Eastern Orthodox Church's Ecumenical Patriarchate of Constantinople until the Turkish parliament enacted a law banning private higher education institutions in 1971.