1353–1354 , Church of
San Nicola (Ottana) In September 1353, feeling threatened by the Aragonese claims of sovereignty and by the consolidation of their power in the rest of the island,
Marianus IV,
judge of Arborea broke the alliance with the Aragonese made by his father. Allied with the Doria he declared war on the Kingdom of Sardinia. The judicial troops penetrated the
Campidano of Cagliari without encountering real resistance from the Aragonese. Many villages rebelled against the Iberian feudal lords and joined the Arborean cause. Marianus's army then occupied the villa of
Quartu Sant'Elena and threatened the nearby city of
Cagliari, the capital of the Sardinian kingdom. On September 18, the Cagliarin councilors of the Aragonese governor, broached the Admiral Bernat de Cabrera for help. Procurement was difficult because Marianus had cut all supplies to Cagliari and
Villa di Chiesa. On October 6 Cabrera, who arrived in the south of the island, defeated the armies of the judge near Quartu and loosened the Arborean siege over the city. Meanwhile, in the north of Sardinia, numerous rebellions raged at the instigation of the Doria. On October 13 the fortress of
Monteleone Rocca Doria rose and
Alghero was reoccupied on October 15. At the end of the month Marianus and Matteo Doria besieged
Sassari with about 400 knights and 1000 infantrymen. At the turn of 1353 the Arborea and the Doria were masters of almost all of Sardinia; only the cities of Cagliari, Sassari, and Villa di Chiesa and some castles remained in the hands of the Kingdom of Sardinia. Marianus possessed considerable military capabilities and, thanks to the sizable export of
grains, his Judicate had the economic resources necessary to support an army able to oppose that of the crown of Aragon. He had infantrymen and knights recruited from the villages, a body of
crossbowmen and soldiers of fortune of various origins (
Italy,
Germany,
France,
England) commanded by expert captains coming from the
Italian peninsula. (
Poblet Monastery) Given the aggravation of the situation, King
Peter IV of Aragon set up an impressive expedition to quell the rebellion on the island. He commanded a large fleet that landed on June 22, 1354, in Porto Conte with the aim of reconquering the city of Alghero. The Aragonese siege, which lasted about five months, ended in a disaster from all points of view, due to the
malaria that caused many victims among the ranks of the besiegers. Marianus, who came near the allied city under siege, came with his troops near
Bosa, but did not fight. In order to avoid a complete defeat, Peter began negotiations with Marianus. On November 13, 1354, the Peace of Alghero was signed, with which Marianus obtained several of his objectives for the revolt: the autonomy of his Judicate, freedom of trade in the Arborean ports, the fief of
Gallura and the clause that the governor general of the kingdom of Sardinia must be a person pleasing to him. Peter IV could in return take possession of
Alghero; the original Sardinian–Ligurian population, being pro-Genoese, was evacuated and replaced by
Catalan colonists.
1365–1388 The peace did not last long and, in 1365, Marianus invaded the Aragonese territories, again entering the Campidano and
Cixerri. He conquered various villages and castles and the mining town of Villa di Chiesa, which rebelled against the Aragonese. In the spring of 1366, he built a fortified camp near
Selargius to block supplies to Cagliari, but the city did not give up. With the support of
Genoa, Marianus also opened a new front in the north of the island. In June 1368 an Aragonese army led by Pedro Martínez de Luna arrived in Cagliari and marched toward the Judicial capital,
Oristano, which until then had never been besieged by Aragonese troops. Hugh, the son of Marianus, came to the rescue of the city with an army recruited in the occupied territories. While the Catalans were preparing for the battle, Marianus left the besieged city, attacking them by surprise and defeating them near Sant'Anna. In 1369, after a brief siege, Sassari was conquered, followed by
Osilo. By 1370 the Aragonese presence in Sardinia had been reduced only to the cities of Cagliari and Alghero and to the castles of
San Michele,
Gioiosa Guardia,
Aquafredda and Quirra. In 1374 the fleet of the Republic of Genoa, in support of Marianus, attacked the port of Cagliari but was rejected by the resistance of the royal troops. Marianus IV died in May 1375 at the height of his power, perhaps hit by the
plague. His firstborn, Hugh, took over with the dynastic name of
Hugh III of Arborea. Hugh continued his father's policy of territorial expansion. However, his military feats were not at same level to those of the father, and the cities of Cagliari and Alghero remained unconquered. His reign was of short duration and, like his ancestor
John of Arborea, Hugh III, together with his only daughter, Benedetta, was assassinated in 1383 during a riot.
Frederick of Arborea succeeded Hugh, followed in 1387 by Marianus V; both were sons of
Eleonora d'Arborea and
Brancaleone Doria. However, being minors the throne was inherited de facto by their mother who in 1388 stipulated a peace treaty with Aragon, committing herself to restitution of the territories conquered by her predecessors.
1390–1420 After a few years the hostilities between the two parties resumed when, freed from the Aragonese, Brancaleone Doria violated the peace treaty signed by his wife and by
John I of Aragon, considering it not valid. On April 1, 1391, he marched against Castel di Cagliari; on August 16, with his son
Marianus V of Arborea alongside, he occupied Sassari and Osilo. In September he conquered the castles of Fava, Pontes, Bonvehì and Pedres, leaving only Alghero and Longosardo to their adversaries. He then entered Villa di Chiesa and
Sanluri. In a letter written to Sanluri on February 3, 1392, Brancaleone announced that he had retaken all the territories owned in 1388. The military operations ended, however, with the Aragonese continuing to control the surrounding sea. In the summer of 1406 Brancaleone resumed the offensive, invading many lands of the former
Judicate of Cagliari and
Ogliastra, occupying the castle of Quirra, attacking Longosardo and besieging Cagliari. Eleonora died early in 1404 and Marianus V in 1407, and Brancaleone fell into disgrace before dying in 1409. The Arborea throne was offered by the
Corona de Logu to
William III of Narbonne (the nephew of Beatrice, who was the sister of Hugh III and Eleonora) who became a judge with the name of William II. Taking advantage of the dynastic crisis, the heir to the crown of Aragon,
Martin I of Sicily the Younger, on October 6, 1408, landed in Sardinia with a powerful army commanded by Pedro Torrelles. After failed attempts to reach an agreement, the war resumed its course. The clash between the two camps
took place in the countryside of Sanluri, in the locality currently called
su bruncu de sa battalla (battle hill), on June 30, 1409. The troops of the Kingdom of Sardinia divided the judicial army, led by William, into two sections. The left side was overwhelmed in the locality called ''s'occidroxiu'' (the slaughterhouse); the right split into two remainders: the first retreated to Sanluri, but was reached and destroyed, the second took refuge in Monreale and resisted. On July 4, Villa di Chiesa surrendered in the hands of Giovanni de Sena. It was a disaster for the Arborea, even if Martin the Young died shortly afterward in Cagliari on July 25, 1409, of malaria, probably contracted after the battle. William III of Narbonne (William II as judge of Arborea) returned to
France to seek help and left, as a
de facto judge, his cousin, Leonardo Cubello, descended from Hugh II. The heavy defeat suffered at Sanluri, however, did not completely bend the Arboreans. The fighting resumed and, on August 17, the judicial army rejected a violent attack against Oristano by the Moncada. The following day Pedro Torrelles led the soldiers of the Kingdom of Sardinia in a battle on the plain between Sant'Anna, Fenosu and
Santa Giusta, remembered as the Second Battle (
Segunda battalla), leaving on the field – according to Spanish sources – more than 6,500 of their men. The conflict was not yet concluded; the army of the Kingdom of Sardinia asked and obtained reinforcements. The Arboreans defended themselves strenuously and seven months passed before Pedro Torrelles conquered the castles of Monreale,
Marmilla and Gioiosa Guardia. In January 1410 Pedro Torrelles occupied Bosa and besieged Oristano, where finally Leonardo Cubello signed, in the church of San Martino outside the walls, the surrender of the city and all of the areas of Arborea that were forfeited in the
Regnum Sardiniae et Corsicae. Oristano and the Campidano of
Cabras,
Milis and
Simaxis were given to him along with the title of
Marquis of Oristano. Remaining Arborean territories included the former Judicate of Torres, two
curatoria of the
Judicate of Gallura and the
Barbagia of
Belvì,
Ollolai and
Mandrolisai. In spring of the same year William II of Narbonne returned from France, organizing the surviving territories and transferring the capital of the Judicate to
Sassari. With the help of Nicolò Doria he resumed the castle of Longosardo and threatened Oristano and Alghero, where Pedro Torrelles, the captain general and lieutenant of the king, died in that year of malaria. The war continued and between May 5 and 6, 1412, managed to enter Alghero with Sassarese and French militiamen, but was then rejected and forced to desist by the fierce resistance of the Algherese. Convinced that he could not improve the situation, William dealt first with King
Ferdinand I of Aragon, then with his son
Alfonso V the Magnanimous. An agreement was reached on August 17, 1420, and what remained of the old Judicate of Arborea was sold for 100,000 gold
florins. == Consequences ==