In 1502, Philip, Joanna and a large part of the Burgundian court travelled to Toledo for Joanna to receive fealty from the Cortes of Castile as Princess of Asturias, heiress to the Castilian throne, a journey chronicled in great detail by Antoon I van Lalaing (). Philip and the majority of the court returned to the Low Countries in the following year, leaving a pregnant Joanna in Madrid, where she gave birth to her and Philip's fourth child, Ferdinand, later a central European monarch and Holy Roman Emperor as Ferdinand I.