Why would you need a claim on the Portuguese crown to take territory from the continent?The Spanish sure didn't need a claim on the Portuguese crown to take Olivenza.The Spanish just need to be able to defeat Portuguese army and whatever contingent the British could send to Portugal.Problem is that the Spanish just seemed utterly incapable of doing so despite having much larger armies than the Portuguese-British allied armies.
This is for a timeline I'm planning where the Franco-Spanish alliance is much stronger. I'd rather not go into the reasons for that so as not to spoil the timeline, but I'd love to hear people's thoughts on how much is reasonable to land grab in a complete success scenario. Obviously they got completely screwed during the Napoleonic wars, but I get the impression that was excessive due to Napoleon breaking the way things were done.
On the other hand, I don't think minor land grabs would reflect the scale of victory in a complete conquest scenario. My three most plausible scenarios, to my mind, are as follows:
a) Spain takes the Algarve and Alentejo, so as to surround Portugal from all three sides in a future war and also get another royal title. (By Alentejo, I mean the smaller older province, rather than the more modern borders.)
b) Spain takes Tras-os-Montes and Minho, so as to easily integrate it into the Kingdom of Galicia fairly easily, and so it is easier to suppress revolts
c) The Spanish King takes the throne of Portugal, but keeps the parliament separate.
Was there ever a case of something like c) happening in this time period? Or would it make Spain utterly hated throughout Europe? I'm thinking a) is most likely, on the basis that it's a similar share of territory to what Prussia would have lost in the Seven Year's War (Silesia to Austria and East Prussia to Russia).
Also, was there any more resentment to Lisbon rule in one part of Portugal or another? I've read that the Portuguese spoken in Alentejo was almost another language.