The office, position, or authority of an archpriest; the rank or jurisdiction held by a chief priest.
Archpriest plus -ship (a suffix meaning office, position, or state). This administrative term appears in ecclesiastical records and governance documents.
Medieval churches used both 'archpriesthood' and 'archpriestship'—they mean basically the same thing, showing how flexible English is at creating formal titles for religious offices.
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