He was the second son of Fernando Álvarez de Toledo, 3rd Duke of Alba, and he became the fourth Duke after his father's death. His titles included Duke of Huéscar, Marquis of Coria and Comendador Mayor in the Order of Calatrava. Don Fadrique, was commander of the Spanish troops during the most bloody phase of the war in the Netherlands. He was in charge of the Spanish troops that slaughered the populations of Mechelen, Zutphen and Naarden, as well as during the costly Siege of Haarlem.