Original: He married Infanta Isabella, the half-sister and heiress of Henry IV of Castile, on 19 October 1469 in Valladolid.
Simplified: He married Infanta Isabella, the sister by a different mother and heiress of Henry IV of Castile, on October 19, 1469 in OcaÃ a/O. He became Ferdinand V of Castile when Isabella succeeded her brother as Queen of Castile in 1474.