Then, in September, after Ferdinand and Isabella had left one bride and groom at Valladolid and gone to the border town of Valencia de Alcantara, to deliver a reluctant but obedient daughter to her second husband, the thunderbolts began to fall. While the festivities on the Portuguese frontier were still in progress a courier brought word that Prince Juan lay dangerously ill at Salamanca. The merrymaking broke up, and Ferdinand, stabbed in his most vulnerable spot, his dynastic ambition, for once outrode his wife, to find his only son dying, to send back falsely hearty reports from the bedside, to consider the ruin of his hopes.
[…]
[Later, after Juan’s death…] For a while the Catholic Kings hoped still to save their dynasty; Margaret was carrying Juan’s child. If it was a boy there would still be one of the house of Trastamara to rule Spain. Then the child was born, prematurely, dead. The crowns of Spain would pass to a foreigner.
Source:
Mattingly, Garrett. “Part I: A Spanish Princess (1485-1509); Chapter 1, Section iii” Catherine of Aragon. New York: Quality Paperback , 1990. 17, 18. Print.
Original Source Listed:
Cal. Span. I, 295 (R.O.).
Further Reading:
Isabel I de Castilla / Ysabel I (Isabella I of Castile)
That room must have gotten really heavy really quick.