The House de la Cerda is a noble line of the Crown of Castile descending from the Infante Ferdinand de la Cerda, eldest son of King Alfonso X.
It was one of four noble lineages that arose directly from the Castilian royal family during the thirteenth century and is the origin of the Dukes of Medinaceli.
Following an unsuccessful invasion by Aragon and Portugal, a peace settlement removed the Infantes de la Cerda from contention for the Castilian throne.
[2] The lineage of de La Cerda continued throughout the Middle Ages and was constituted as a noble house of the first rank, playing a leading role in Castilian politics.
This line, like others from the Civil War of the mid-fourteenth century, continued through the female line to shift the family heritage until Dona Isabel de la Cerda married Bernal de Foix, first Count of Medinaceli.