When Alphonso died in 1291 James became king of Aragon, and left his brother Frederick as regent of Sicily.
They were fanatical, and their tyranny drove numbers of their Jewish and Christian subjects to take refuge in the growing Christian states of Portugal, Castile and Aragon.
An important event of his pontificate was the capture of Granada (2nd of January 1492), which was celebrated at Rome with great rejoicing and for which Innocent gave to Ferdinand of Aragon the title of "Catholic Majesty."
In his youth he was one of the infantes (princes) of Aragon who took part in the dissensions of Castile during the minority and reign of John II.
Till middle life he was also lieutenant-general in Aragon for his brother and predecessor Alphonso V., whose reign was mainly spent in Italy.