DUKE-Duke, a quality given in Spain to a grandee of the house of Silva, on account of his having several duchies from the uniting of two considerable houses in his person. Don Roderigo de Silva, eldest son of Don
Dulcifying Dumbness. Ruy Gomez de Sylva, and heir of his duchies and principalities, married the eldest daughter of the Duke de l'Infantado; in virtue of which marriage, the present Duke de Pastrana, who is descended therefrom, and is grandson of Don Roderigo de Sylva, has added to his other great titles that of duke-duke, to distinguish himself from the other dukes; some whereof may enjoy several duchies, but none so considerable ones, nor the titles of such eminent families.