Etymology
From Middle English patriark, patriarche, from Late Latin patriarcha; later reinforced by Old French patriarche, from Ancient Greek πατριάρχης (patriárkhēs, “the founder of the tribe/family”), from Ancient Greek πατριά (patriá, “generation, ancestry, descent, tribe, family”) + -ᾰ́ρχης (-ắrkhēs, “-arch”), with some senses likely influenced directly by Latin pāter (“father”) or Ancient Greek πᾰτήρ (pătḗr, “father”). Compare matriarch. By surface analysis, patri- + -arch.