sentences:  Eleanor immediately set to work defeating the rebels and securing her son's realm.No sooner, the Giudicato fell into another bitter war with the Crown of Aragon, who laid claim to the island.During the war, Frederick was captured together with his father by its monarch Peter IV of Aragon, and they both were imprisoned in Cagliari, first in the tower of San Pancrazio and then in that of Elefante.