The Kalinga War is fought between the…

Martin, the second son of King Peter IV of Aragon and Eleanor of Sicily (Leonora of Trinacria), princess of the Sicilian branch of the House of Aragon, had succeeded his elder brother John I, who had died sonless in 1396, on the throne of Aragon.

However, Sicilian nobles had been causing unrest and Martin had been kept in Sicily.

Meanwhile, Martin's wife María López de Luna, daughter and heiress of Lopez de Luna, Lord and 1st Count of Luna and Lord of Segorbe and wife, a relative of Pope Clement V, had claimed the throne on behalf of Martin and acts as his representative until he arrives in 1397.

Still, the delay has opened the way for more problems and quarrels to surface in Aragon.

His right to the throne is contested, first by Count Matthew of Foix on behalf of his wife Joanna, elder daughter of John I.

However, Martin succeeds in quashing the invasion by the troops of the count.

Martin launches crusades against the Moors in North Africa in 1398 and 1399.

The antipope Benedict, besieged in his palace for the past five years, had managed to escape from Avignon on March 12, 1403 and seek shelter in territory belonging to Louis II of Anjou.

By this stage, Benedict's authority is no longer recognized in France, Portugal and Navarre, but he is acknowledged as pope in Scotland, Sicily, Castile, and Aragon, where Benedict flees to the protection of Martin I.

Aragon had been trying to subjugate Sardinia since the reign of James II, and gradually the Aragonese had conquered most of the island.

However, in the 1380s, in the reign of Martin's father Peter IV, the remaining independent principality of Arborea had become a fortress of rebellion and the Aragonese were rapidly driven back by Eleanor of Arborea, so that practically the whole of Sardinia had been lost.

William III, Viscount of Narbonne, is the grandson of Beatrice, youngest daughter of Marianus IV of Arborea and Timbra de Rocabertí, and Aimery VI of Narbonne (married 1363).

When Marianus V, the youngest son of Beatrice' elder sister Eleanor, died in 1407, Arborea had experienced a succession crisis.

The late Beatrice had a claim to the judgeship which was picked up by her grandson, the son of William II.

The de jure judge from 1407 is Leonardo Cubello, great nephew of Hugh II of Arborea.

King Martin of Aragon has sent his son Martin the Younger, King of Sicily, to reconquer Sardinia.

On October 6, 1408, Martin had disembarked at Cagliari with a strong army.

On December 8, William had also reached Cagliari, and is crowned "King of Arborea, Count of Goceano, and Viscount of Bas" at Oristano on January 13, 1409.

Martin, just weeks before his death at Cagliari from malaria on July 25, had won the Battle of Sanluri (San Luis, San Luigi) on June 30, 1409, driving away the Genoese allies of the Sardinians, and subjugating a vast number of Sardinian nobles.

This will soon cause Arborea's total loss of independence.

Martin succeeds his late son as King of Sicily, as Martin II.

Overall, the Kingdom of Aragon enjoys external peace during Martin's reign and he works to quell internal strife caused by nobles, factions and bandits.

He supports the Avignon line of Popes and an Aragonese, Pope Benedict XIII, will hold the seat throughout Martin's reign.

Martin's military intervention had rescued the imprisoned Benedict in 1403 from the clutches of his rivals and the Pope had settled in Valencia's countryside.

The Aragonese capture Oristano, capital of the Giudicato di Arborea in Sardinia.

William III of Narbonne, having returned to Sardinia in spring 1410, reorganizes his territories with his capital at Sassari.

With the help of Nicolò Doria, he recaptures Longosardo on August 9, and tries unsuccessfully to retake Oristano and …

…Alghero.

William III of Narbonne enters Alghero on May 5-6, 1412, but the citizenry drives him off.