He inherited a claim to the Aragonese throne through his maternal grandfather James II, Count of Urgell, who was the last male descendant of the House of Barcelona and heir to the Crown of Aragon by the rights of agnatic primogeniture.
By inheriting from his maternal grandfather, James II, Count of Urgell, who was the last male in the line of succession from the House of Barcelona and had inherited the throne through agnatic primogeniture rights, he became the rightful heir to the Aragonese throne.