In 1391, the war against the Aragoneses burst again by the same Brancaleone, yearning for redemption. “Villa di Chiesa” ( Villa of Church in Iglesias) and Sanluri had been reconquered, but the Aragoneses managed to defend the main strongholds, such as Cagliari and Alghero. After reaching majority age, flanked by his father Brancaleone, Mariano V was left in charge of the Giudicato. In 1396 , Giovanni I died and, at the same time, his brother Martino became the king of Aragona.
In 1407, Mariano V perished also at a young age. When the Giudicato was entrusted to Guglielmo III of Narbona (grandson of Beatrice, sister of Eleonora), it was the time of the final battle between Arborea and Aragon, with the epic clash in front of the castle of Sanluri, in 1409, that registered the Victoria of the Aragoneses. Guglielmo III, subjected tothe French king and great general in the “Guerra dei Cent’anni” ( Hundred Years War) against England, returned to France in order to reorganize the troops, entrusting the Giudicato to the cousins Leonardo Cubello, but this was the beginning of the end of the “Giudicato d’Arborea”.