大公の役割は何？
Archduke (feminine: Archduchess; German: "Erzherzog", feminine form: "Erzherzogin") was the title borne from 1358 by the Habsburg rulers of the Archduchy of Austria, and later by all senior members of that dynasty. It denotes a rank within the former Holy Roman Empire (962–1806), which was below that of Emperor and King and above that of (debatably) a Grand Duke, Duke and Prince.
rulers of the Archduchy of Austria