In ecclesiastical usage, patriarchate denotes the administrative sphere of a patriarch. Since late antiquity, patriarch (Greek patriárches - a compound of patḗr, “father,” and árchein, “be a commander,” “rule” – originally meaning “clan chief” or “progenitor”) was a title of senior Christian clergy. As early as the first ecumenical Council of Nicaea (325), we can see a regional structure of the church…