Don Ferdinand de la Cerda (1253–1275) was the Crown Prince (infante) of Castile, eldest son of King Alfonso X of Castile and Violant of Aragon. His nickname, de la Cerda, means "of the bristle" in Spanish, a reference to being born with a strand of thick hair running down his chest.
Alfonso de la Cerda , who married Matilde of Narbonne, daughter of Viscount Aimery VI of Narbonne.Medieval Iberia: An Encyclopedia, Ed. E. Michael Gerli and Samuel G. Armistead, (Routledge, 2003), 50. They had four sons and three daughters.
Ferdinand predeceased his father in 1275 at Ciudad Real. His sons did not inherit the throne of their grandfather, since their uncle Sancho, usurped the throne.