So, the challenge here is to have Spain and Portugal unite politically, with a PoD after 1640.
Bonus points if you manage to create a republican Iberian Union.
Bonus points if you manage to create a republican Iberian Union.
This will probably need Spain to have fractured for a long period first.
Isabel II of Spain could marry Pedro V of Portugal or any of his brothers. Or maybe Isabel II dies and is succeeded by her younger sister, and she could marry one of the Portuguese princes (who presumably don't die of illness TTL). A child by them would be monarch of both countries.
IIRC this was proposed by some Portuguese politicians of the era but nothing more was done with the proposal.
The first republic lasted too long for what it was. It is impossible for it to last longer unless you change Spanish republicanism in the XIX century as a whole.Bumping.
Could a surviving First Spanish Republic from the 1870's on in somehow lead to a republican Iberian Union if Portugal still throws its king out?
I hear that some top officials in the First Republic's government were iberistas.