IOTL Ferdinand II of Aragon became King of Castile iure uxoris as husband of Isabel of Castile, but as descendant of Juan I of Castile he was himself high in succession line, just behind Isabel and their children. So lets say that following changes happen-la Beltraneja dies as kid, while Isabel (now undisputed heiress of her brother Enrique) still marries Fernando like IOTL, but dies giving birth to their first child in 1470. That leaves Fernando's father Juan II of Aragon as closest legitimate relative of Enrique IV. My question is-would Juan, who is in his 70s, claim Castilian throne for himself, or would he leave it for his son and successor? Even if former happens Juan would not reign long anyway, so we'd see Fernando rulling Castile on his own right for few decades. Considering the fact, that he seemed saner than his wife, how would Castile looks like under his rule? Torqemada not rising to OTL position seems obvious, but what else would change? What about fate of Granada or Christopher Columbus?