Late 18th century; earliest use found in Jacob Bryant (bap. 1717, d. 1804), antiquary and classical scholar. From post-classical Latin patriarchicus relating to biblical patriarchs, relating to patriarchs in the Christian church from Byzantine Greek πατριαρχικός relating to biblical patriarchs, relating to patriarchs in the Christian church from Hellenistic Greek πατριάρχης + -ικός.