The field of education attracted the keen interest of the Church's pastors early on, both for the service of the practical needs of worship life and for the exercise of its teaching and missionary work. In particular, the Ecumenical Patriarchate of Constantinople, as the administrative and spiritual center of Orthodoxy, took special care to promote and strengthen Greek school education in the areas under its jurisdiction, especially during the period of Ottoman domination. This study attempts a systematic investigation of the role and contribution of the Patriarchate, as well as the Patriarchs of the Church of Jerusalem, in the establishment, organization, and operation of Greek schools based on patriarchal and synodal documents from the period 1593-1821.