Ferdinand married for a second time to Maria Luisa de Silva y Fernández de Henestrosa, Duchess of Talavera de la Reina, daughter of Luis de Silva y Ferandez, 10th Count of Pie de Concha and his wife Maria de los Dolores Fernandez de Henestrosa y Fernández de Córdoba, on 1 October 1914 in Fuenterrabía, Spain.
When the daughter, Berengaria, of Alfonso X of Castile was betrothed to Louis, eldest son and heir of King Louis, Castile ceded the use of the ports of Fuenterrabía and San Sebastián to Navarre on 1 January 1256.