The difficulty became more acute when Joan gave birth to her son at Ghent in February 1500, because, according to the law of succession, the child christened Charles, a name unheard of in Spain before, would inherit, not Castile and Leon alone, but Aragon as well, with Flanders, Burgundy, Artois, Luxembourg, the Aragonese kingdoms in Italy, and, worst of all, Austria and the empire. Where would the interests of Aragon, nay, even of Spain, be amongst such world-wide dominions; and how could such a potentate devote himself either to aggrandising Aragon, or to carrying the Cross into the dark places of Moorish Africa? What added to the bitterness in Ferdinand’s case was, that Philip was even now intriguing actively with the Kings of France, Portugal, and England against Aragon; and was, with vain pretexts, evading the pressing invitations of his wife’s parents to bring her to Spain, to receive with him the oath of allegiance as heirs of the realms.
It was necessary somehow to conciliate Philip and Joan before they went too far; for Philip’s plan, to marry the infant Prince Charles to a French princess, struck at the very root of Ferdinand’s policy. Envoy after envoy was sent to Flanders to expedite the coming of Philip and Joan, if possible, with the infant Charles; but the Archduke had no intention of becoming the tool of his astute father-in-law, and was determined to be quite secure before he placed himself in his power. He was anxious enough to obtain recognition as heir of Castile jointly with his wife, but desired to leave Spain immediately afterwards, which did not suit Ferdinand, who wished to have time to influence him towards his policy, and alienate him from his Flemish and French favourites.[90] Joan herself flatly refused to come without her husband; of whom, with ample reason, she was violently jealous; and neither would allow the infant Charles to come without them. At length, after Joan had been delivered of her third child, a daughter named Isabel, the prayers and promises of Queen Isabel and her husband prevailed, and the Archduke and Archduchess consented to come to Spain. But it was under conditions that turned the heart of Ferdinand more than ever against his son-in-law. They would travel to Spain through France, and ratify in Paris the betrothal of their one-year old son Charles, heir of Spain, Flanders, and the empire, with Claude of France, child of Louis XII. Philip went out of his way during the sumptuous reception in Paris to show his submission to the King of France; and even did homage to him as Count of Flanders; but Joan, mindful for once, at least, that she belonged to the house of Aragon, and was heiress of Spain, refused all tokens implying her subservience.