How successfully did Ferdinand and Isabella consolidate royal authority from 1474 to 1492?

Upon becoming the joint monarchs of Castile and Aragon, one of the main challenges that Ferdinand and Isabella faced was to extend the crown's authority over the Iberian peninsula thus increasing the stability of the kingdom and power of the crown. This was a daunting task, especially given the power of grandees such as Mendoza and Carillo at the time. The Catholic kings had some considerable success in consolidating royal authority, but there were limitations …

…from a dire state in the same way that it did in Castile) but the crown did little to fundamentally extend its power. Ferdinand spent most of his time in Castile (and later in Naples) where Ferdinand had much more power rather than Aragon. It is therefore perhaps slightly unfair to evaluate his success in Aragon when primarily his goal was to help consolidate royal power in Castile; definitely the dominant partner in the relationship.