So, basically the title, but why didn't they? I think there was the Iberian Union once, but that was rather peaceful, wasn't it? It also seems pretty profitable for the Spanish to not only get rid of their arch-enemy in the west, especially after its alliance with France. But also to consume Brazil and then have full control over South America. I also imagine that Britain would not be that huge of a oroblem to the Spaniards, after their alliance with France, as they would have probably clashed with them enough.
For Clarification: With French-Spanish Alliance I mean their shared Bourbon throne after the war of spanish succession.
Hey there,
Just to let you know, your question is fine, and we're letting it stand. However, you should be aware that questions framed as 'Why didn't X do Y' relatively often don't get an answer that meets our standards (in our experience as moderators). There are a few reasons for this. Firstly, it often can be difficult to prove the counterfactual: historians know much more about what happened than what might have happened. Secondly, 'why didn't X do Y' questions are sometimes phrased in an ahistorical way. It's worth remembering that people in the past couldn't see into the future, and they generally didn't have all the information we now have about their situations; things that look obvious now didn't necessarily look that way at the time.
If you end up not getting a response after a day or two, consider asking a new question focusing instead on why what happened did happen (rather than why what didn't happen didn't happen) - this kind of question is more likely to get a response in our experience. Hope this helps!