Hierarchy
late Middle English: via Old French and medieval Latin from Greek hierarkhia, from hierarkhēs ‘sacred ruler’ (see hierarch). The earliest sense was ‘system of orders of angels and heavenly beings’; the other senses date from the 17th century.
wiktionary
From Middle English ierarchie, jerarchie, from Old French ierarchie, jerarchie, from Late Latin ierarchia, from Latin hierarchia, from Ancient Greek ἱεραρχία(hierarkhía, “rule of a high priest”), from ἱεράρχης(hierárkhēs, “high priest”), from ἱερός(hierós, “holy”) + ἄρχω(árkhō, “I rule”). The H was re-added c. 1500 due to influence from Classical Latin.
etymonline
hierarchy (n.)
late 14c., jerarchie, ierarchie, "rank in the sacred order; one of the three divisions of the nine orders of angels;" loosely, "rule, dominion," from Old French ierarchie (14c., Modern French hiérarchie), from Medieval Latin hierarchia "ranked division of angels" (in the system of Dionysius the Areopagite), from Greek hierarkhia "rule of a high priest," from hierarkhes "high priest, leader of sacred rites," from ta hiera "the sacred rites" (neuter plural of hieros "sacred;" see ire) + arkhein "to lead, rule" (see archon). Sense of "ranked organization of persons or things" first recorded 1610s, initially of clergy, sense probably influenced by higher.
