I mean OTL king Henry VIII of England to be clear. How could this happen? I see two options-in both of them Arthur Tudor, Prince of Wales need to survive to adulthood and preferably left heir (s).
1) Miguel da Paz (born1498), grandson of Catholic Monarchs-queen Isabella of Castille and king Ferdinand of Aragon is born as girl (she will be named Isabella propably, after her mother, lets call her Isabella da Paz, to avoid confusion with other Isabellas). Her mother, princess Isabella, oldest daughter of Catholic Monarchs dies in childbirth like in OTL and baby's father-Manuel of Portugal married again-to his first wife's younger sister Mary, like IOTL and have at least one surviving son with her. In such case his son (call him John) will succeed him on Portuguese throne, but Isabella da Paz would have better claims to Castilian and Aragonese crowns than John, being descendant of Catholic Monarchs oldest daughter. So after death of queen Isabella I in 1504 Isabella da Paz became queen of Castille as Isabella II. Of course under regency of her grandfather Ferdinand. At the time of Ferdinand's death in 1516 she will be 18 years old and propably married. If Ferdinand failed to produce male heir from second marriage like OTL she will take Aragonese Crown as well. So what if by this time she was married to Henry? That will not be first Iberian marriage of Tudor prince because in this TL aunt of Isabella II, Catherine of Aragon is wife of Arthur Tudor. I think Henry-Isabella marriage is possible-Ferdinand should like that idea because it would strenghten alliance with England against France. What is your opinion?
And about second option-I
will present it later.
1) Miguel da Paz (born1498), grandson of Catholic Monarchs-queen Isabella of Castille and king Ferdinand of Aragon is born as girl (she will be named Isabella propably, after her mother, lets call her Isabella da Paz, to avoid confusion with other Isabellas). Her mother, princess Isabella, oldest daughter of Catholic Monarchs dies in childbirth like in OTL and baby's father-Manuel of Portugal married again-to his first wife's younger sister Mary, like IOTL and have at least one surviving son with her. In such case his son (call him John) will succeed him on Portuguese throne, but Isabella da Paz would have better claims to Castilian and Aragonese crowns than John, being descendant of Catholic Monarchs oldest daughter. So after death of queen Isabella I in 1504 Isabella da Paz became queen of Castille as Isabella II. Of course under regency of her grandfather Ferdinand. At the time of Ferdinand's death in 1516 she will be 18 years old and propably married. If Ferdinand failed to produce male heir from second marriage like OTL she will take Aragonese Crown as well. So what if by this time she was married to Henry? That will not be first Iberian marriage of Tudor prince because in this TL aunt of Isabella II, Catherine of Aragon is wife of Arthur Tudor. I think Henry-Isabella marriage is possible-Ferdinand should like that idea because it would strenghten alliance with England against France. What is your opinion?
And about second option-I
will present it later.