[2] During his youth and early adulthood, Peter gained a great deal of military experience in his father's wars of the Reconquista against the Moors.

[4] Peter's first act as king was to complete the pacification of his Valencian territory, an action which had been underway before his father's death.

However, a revolt soon broke out in the Principality of Catalonia, led by the viscount of Cardona and abetted by Roger-Bernard III of Foix, Arnold Roger I of Pallars Sobirà, and Ermengol X of Urgell.

In 1278, Ermengol X, Àlvar's eldest son, succeeded in recovering most of his lost patrimony and came to an agreement with Peter whereby he recognised the latter as his suzerain.

[3] In 1280, Peter defeated the stewing rebellion led by Roger-Bernard III after besieging the rebels in Balaguer for a month.

It was these Aragonese troops that received a Sicilian embassy after the Vespers of 30 March asking Peter to take their throne from Charles I of Anjou.

John travelled to Sicily to stir up the discontents in favour of Peter and thence to Constantinople to procure the support of Michael VIII Palaiologos.

[7] Michael refused to aid the Aragonese king without papal approval, and so John voyaged to Rome and there gained the consent of Pope Nicholas III, who feared the ascent of Charles in the Mezzogiorno.

A hundred knights would accompany each side and Edward I of England would adjudge the contest; the English king, heeding the pope, however, refused to take part.

Peter left John of Procida in charge of Sicily and returned via his own kingdom to Bordeaux, which he entered in disguise to evade a suspected French ambush.

On 30 March 1282 there was a popular uprising in the Kingdom of Sicily called the Sicilian Vespers, against the government of Charles I of Anjou.

[9] Catalan ground troops were commanded by Guillem Galceran de Cartellà, and were formed by the famous and feared almogavars, crossbowmen, and lancers.

Peter's powerful fleet was commanded by Roger of Lauria, and constantly repelled Angevin attacks to the island.

He took Albarracín from the rebellious noble Juan Núñez de Lara, he renewed the alliance with Sancho IV of Castile, and he attacked Tudela in an attempt to prevent Philip I of Navarre from invading on that front.

The French soon experienced a reversal, however, at the hands of Roger de Lauria, back from the Italian theatre of the drawn-out conflict.

The King of Navarre, the heir apparent to the French throne, opened negotiations with Peter for free passage for the royal family through the Pyrenees.

Philip III of France died in October at Perpignan, the capital of James II of Majorca (who had fled in fear after being confronted by Peter), and was buried in Narbonne.

The second is part of a compilation of five compositions from Peter himself, Bernat d'Auriac, Pere Salvatge, Roger-Bernard III of Foix, and an anonymous contributor.

As well the wars with Philip III of France and James II of Majorca furnished material for new sirventesos and during this period the sirventes was converted into a convenient tool of political propaganda in which each side could, directly or allegorically, present its case and procure sympathy propitious to its cause.

Peter died from unknown causes at Vilafranca del Penedès in November 1285,[11] just one month after Philip III of France, and was buried in the Monastery of Santes Creus.