One of the ancient fathers of Judaism and Christianity — Abraham, Isaac and Jacob. In the Eastern and Oriental Orthodox churches, a patriarch is the highest-ranking bishop. Capitalize if used before a name. In the Roman Catholic Church, the patriarch is the bishop of Rome and is called pope. Unlike the pope, who has jurisdiction over all Roman Catholic territories, the authority of Eastern and Oriental patriarchs is more limited. They have a great deal of enforceable jurisdiction in their own territories but no authority over each other’s.