Duke of Frías is a hereditary title in the peerage of Spain accompanied by the dignity of Grandee, created in 1492 by King Ferdinand II of Aragon and conferred to his son-in-law Don Bernardino Fernández de Velasco, 2nd Count of Haro, Constable of... Wikipedia
First holder: Bernardino Fernández de Velasco, 1st Duke of Frías
Present holder: Francisco de Borja de Soto y Moreno-Santamaría, 19th Duke of Frías