 After the reconquest of Zaragoza in 1118 by Alfonso of Aragon "the Battler", the Aljafería became the residence of the Christian kings of Aragon, becoming the main focus of the Aragonese Mudejar diffusion.It was used as a royal residence by Peter IV of Aragon "the Ceremonious" and later, on the main floor, was carried out the reform that turned these paradors into the palace of the Catholic Monarchs in 1492.In 1593 it underwent another reform that would make it into a military fortress, first according to Renaissance designs (which today can be seen in their surroundings, pit and gardens) and later as a quarters of military regiments.