OTL Isabel II's marriage (and that of her younger sister) caused quite a bit of tension between France and Britain. The British wanted one prince, Louis Philippe another, and basically how it ended up was that Isabel was married to Francisco d'Asis, Duke of Cadiz, with the marriage of her younger sister to one of Louis Philippe's sons.
LP wanted Cadiz because he'd heard that the prince was possibly impotent (IIRC he had to urinate sitting down for some medical reason), which would've increased the chances of the Spanish crown landing on the head of one of Louis Philippe's grandchildren. Isabel didn't like Cadiz too much, as their children were all given nicknames based on her favourite at the time of their conception (can't remember the others, but Alfonso XII was puigmoltijo), and when asked about it, she said: "it was rather hard to care for a man who wore more lace than I on our wedding night".
Now for the POD. What if, somehow, Isabel is married to Francisco d'Asis' brother, Enrique, duke of Seville instead. Enrique was a liberal, and by all accounts, the opposite of his brother (and I think I read somewhere that he was Isabel's preferred choice). Say either Francisco is either unavailable (already married, perhaps? His sisters almost all contracted matches that made Isabel blush, so I wouldn't say he's immune to such stupidity) or dead (I'd say killed in action, but that seems rather unlikely), and thus the marriage goes through. What happens next?
LP wanted Cadiz because he'd heard that the prince was possibly impotent (IIRC he had to urinate sitting down for some medical reason), which would've increased the chances of the Spanish crown landing on the head of one of Louis Philippe's grandchildren. Isabel didn't like Cadiz too much, as their children were all given nicknames based on her favourite at the time of their conception (can't remember the others, but Alfonso XII was puigmoltijo), and when asked about it, she said: "it was rather hard to care for a man who wore more lace than I on our wedding night".
Now for the POD. What if, somehow, Isabel is married to Francisco d'Asis' brother, Enrique, duke of Seville instead. Enrique was a liberal, and by all accounts, the opposite of his brother (and I think I read somewhere that he was Isabel's preferred choice). Say either Francisco is either unavailable (already married, perhaps? His sisters almost all contracted matches that made Isabel blush, so I wouldn't say he's immune to such stupidity) or dead (I'd say killed in action, but that seems rather unlikely), and thus the marriage goes through. What happens next?