Patriarchate (/ˈpeɪtriɑːrkɪt, -keɪt/, UK also /ˈpætri-/; Ancient Greek: πατριαρχεῖον, patriarcheîon) is an ecclesiological term in Christianity, referring to the office and jurisdiction of a patriarch.
According to Christian tradition, three patriarchates—Rome, Antioch, and Alexandria—were established by the apostles as apostolic sees in the 1st century. These were officially recognized by the First Council of Nicaea. The Patriarchate of Constantinople was added in the 4th century, and the Patriarchate of Jerusalem followed in the 5th century. These five sees were later recognized collectively as the pentarchy by the Council of Chalcedon in 451.