In order to achieve an alliance with Queen Isabella I of Castile and King Ferdinand II of Aragon, Maximilian started negotiating the marriage of their only son and heir, John, Prince of Asturias, to Margaret, as well as the marriage of their daughter Juana to Philip. Margaret left the Netherlands for Spain late in 1496. Her engagement to the Prince of Asturias seemed doomed when the ship carrying her to Spain hit a storm in the Bay of Biscay. In haste, she wrote her own epitaph should she not reach Spain: