Archon

Archon (Gr. ἄρχων, pl. ἄρχοντες) is a Greek word that means "ruler" or "lord," frequently used as the title of a specific public office. It is the masculine present participle of the verb stem ἀρχ-, meaning "to rule," derived from the same root as monarch, hierarchy, and anarchy.

Read more about Archon:  Ancient Greece, Byzantine Empire, Ecumenical Patriarchate of Constantinople, Gnosticism