Isabella I of Castile and Alfonso V of Portugal

Queen Isabella I of Castile had a choice of two potential husbands.
They were King Alfonso V of Portugal and King Ferdinand of Aragon.
Isabella married Ferdinand.
Suppose Queen Isabella had married King Alfonso V. What happens then?
 
Some interesting butterflies here.

The immediate effects, I guess, are:

- Spain is not united, because it effectively was born from the personal union betwen the Castillian and Aragonese Crowns under one monarch. Now we have the entire peninsula except Aragon united under the scions of this marriage. Depending on the personal interests and affiliations of the future Portuguese+Castillian King... we might see a more Castillian Portugal or a more Portuguese Castille, either which is a fascinating scenario, in my opinion.

- Inexistent Spain has no business in Italy... I might be mistaken, but if I recall correctly, the claims the Spanish monarch had on Italy derived from their Sicilian interests (which itself came from Aragon, not Castille), and it was enough to oppose the French invasion under Charles VII which sparked the Italian Wars. Obviously, Aragon itself will be interested in securing their Italian possessions, which will put them in conflict with the French (specially considering they already had a lot of "bad blood" against them since the Sicilian Vespers).

- Again, I might be mistaken, but it was due to Isabella's support that the Spanish monarchs financed Christopher Colombus' voyage. Perhaps, if she convinces her husband Alfonso V, the Portuguese will be acclaimed with the discovery of the Americas :D

Finally, considering that IOTL Ferdinand and Isabella had but one daughter (Joan "the Mad"), who married the Habsburg son of the Holy Roman Emperor, Spain doesn't gets under the hold of the Habsburgs... which itself butterflies away a lot of 16-17th Century History... perhaps the Netherlands doesn't even comes to pass (because the country appeared united against the Spanish oppression).
 
If the end result of a Portuguese-Castillian union between Isabella and Alfonso V is another single daughter, then it isn't far-fetched to see another Miguel da Paz situation play out with the daughter marrying the scion of the Aragonese throne. Although this union would probably be dominated from Lisbon, with power unlikely to shift back to Castille once Portugal's fortune is made from trade in the Far East.
 
Finally, considering that IOTL Ferdinand and Isabella had but one daughter (Joan "the Mad"), who married the Habsburg son of the Holy Roman Emperor, Spain doesn't gets under the hold of the Habsburgs... which itself butterflies away a lot of 16-17th Century History... perhaps the Netherlands doesn't even comes to pass (because the country appeared united against the Spanish oppression).

Um...Catherine of Aragon would like a word with you. As would her sisters, the princess of the Asturias and the queen of Portugal.:confused:
 
Actually this marriage was set up to sideline Isabel. There were two heiresses to Castille. One was the King Enrique's half sister Isabel and the other his daughter Juana was might have been a bastard. Juana's mother Juana of Portugal set the match between Isabel and her brother Alfonso V of Portugal to neutralize Isabel's claim. Isabel winning the throne of Castille is definitely not a given if she marries Alfonso.
 
Actually this marriage was set up to sideline Isabel. There were two heiresses to Castille. One was the King Enrique's half sister Isabel and the other his daughter Juana was might have been a bastard. Juana's mother Juana of Portugal set the match between Isabel and her brother Alfonso V of Portugal to neutralize Isabel's claim. Isabel winning the throne of Castille is definitely not a given if she marries Alfonso.

The plan was that Isabel would marry the old king Alfonso V and Juana should marry the king's son, the future John II. So, this way, they would ensure that Castile would unite with Portugal (or, if Juana is childless, that the House of Aviz would rule Castile).
 
The children of Isabella I and Alfonso V are:
Infante John
Infanta Urraca
Infante Alfonso
Infanta Eleanor
Infante Duarte (Edward)
 
The plan was that Isabel would marry the old king Alfonso V and Juana should marry the king's son, the future John II. So, this way, they would ensure that Castile would unite with Portugal (or, if Juana is childless, that the House of Aviz would rule Castile).

This would also deprive Isabel and her descendants of any power, which is why neither her nor her supporters accepted it.
 
IMO, the union of Portugal-Castilla would probably mean less involvement in European Wars, more colonial investment, and possibly a more lenient religious situation.
 
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Some interesting butterflies here.

The immediate effects, I guess, are:

- Again, I might be mistaken, but it was due to Isabella's support that the Spanish monarchs financed Christopher Colombus' voyage. Perhaps, if she convinces her husband Alfonso V, the Portuguese will be acclaimed with the discovery of the Americas :D

Isabel supported Columbus because she thought Castile-Aragon ought to have something to compete with Portugal's voyages down the coast of Africa. If she and Alfonso rule Portugal-Castile, then there is no for additional expeditions; the New World may not be discovered for another generation.

Finally, considering that IOTL Ferdinand and Isabella had but one daughter (Joan "the Mad"), who married the Habsburg son of the Holy Roman Emperor, Spain doesn't gets under the hold of the Habsburgs...

IOTL, F&I had five children (not counting stillbirths).

  • Isabella - married Crown Prince Alfonso, grandson of Alfonso V. He died in a riding accident after only a year. She became demented with grief and guilt. Remarried to Prince Alfonso's uncle Manuel I, she bore one child, but due to her continual fasting and scourging, died an hour later; her son Miguel lived two years.
  • Juan - married Margaret of Austria, died at age 19 of tuberculosis.
  • Juana the mad - mother of Charles V.
  • Maria - married Manuel I, and had eight living children.
  • Caterina - married Crown Prince Arthur of England and then his brother Henry VIII; mother of Mary I of England.
But yes, switching the marriage of Isabella of Castile to Alfonso instead of Ferdinand very probably eliminates the Hapsburg marriage and inheritance of Spain. OTOH a Hapsburg marriage and inheritance of Aragon is still possible.
 
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