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