A prince of the imperial family of Austria.

a sovereign prince of the former ruling house of Austria

The noble title of Archduke (feminine: Archduchess) (German: Erzherzog, fem; Erzherzogin) denotes a rank above Duke and under King, but is too rare and yet has uses too diverse to be given a fixed relative position within the former Holy Roman Empire to which vast European territory it was restricted.

The Archdukes are a genus (Lexias) of tropical forest-dwelling butterflies that are common throughout Southeast Asia and Australasia. Members of the brush-footed butterfly family Nymphalidae, the genus is represented by about 17 species. Two very similar and coexisting genera are Tanaecia (the Viscounts and Earls) and Euthalia (the Barons and Counts), the latter previously including some Lexias species.