An old thread that I found which is a pretty interesting POD:
@Gonzaga
While doing some research about the late reign of Philip II of Spain I've found this information from a review of El Marqués de Velada y la Corte en los Reinados de Felipe II y Felipe III, by Santiago Martínez Hernández. It's about the travel made by Philip II to Aragon to bid farewell to his daughter Catherine after her marriage to the Duke of Savoy:
"...Philip and his court were away from Madrid from January 1586 until March 1586 ... The jornada de Aragón had traumatic consequences for the king himself, for while Philip II was in the mountains of Aragon he suffered a grave illness that all but killed him, and he never again enjoyed robust health. In his growing debility he was obliged to rely increasingly upon his inner circle of ministers..."
So, WI Philip had died while in the mountains of Aragon? Philip III is still a child, so a regency happens, but who would rule? There is Philip's daughter Isabel, but would his ministers accept that? How would Philip's death affect the Armada (how it still happen)?
@Gonzaga