Peter III of Aragon

Peter III
A croat minted at Barcelona, bearing the image of Peter and the words Petrus Dei gracia rex (Peter by the grace of God king) and civitas Barcenona (city of Barelona)
King of Aragon and Valencia Count of Barcelona
Reign	27 July 1276 – 11 November 1285
Coronation	November 1276 (Zaragoza)
Predecessor	James I
Successor	Alfonso III
King of Sicily
Reign	4 September 1282 – 11 November 1285
Coronation	9 November 1282 (Palermo)
Predecessor	Charles I
Successor	James II
Born	c. 1239 Valencia
Died	11 November 1285 (aged 45–46) Vilafranca del Penedès
Burial	Santes Creus
Consort	Constance of Sicily
Issue	Alfonso III, King of Aragon James II, King of Aragon Elisabeth, Queen of Portugal Frederick II, King of Sicily Yolanda, Duchess of Calabria
House	House of Barcelona
Father	James I of Aragon
Mother	Violant of Hungary
Religion	Roman Catholicism

Peter the Great (Catalan: Pere el Gran, Aragonese: Pero lo Gran; 1239 – 11 November 1285) was the King of Aragon (as Peter III) of Valencia (as Peter I), and Count of Barcelona (as Peter II) from 1276 to his death. At the invitation of some rebels, he conquered Sicily and became its king in 1282, pressing the claim of his wife, Constance. He was one of the greatest of medieval Aragonese monarchs.

Peter was the eldest son of James I of Aragon and his second wife Violant of Hungary. Among (opportunistic) betrothals of his youth, he was betrothed to Eudoxia Laskarina, the youngest daughter of Emperor Theodoros II of Nicaea, in or before 1260. This contract was dissolved, however, after Eudoxia's brother lost the imperial throne in 1261, and Eudoxia was instead married to the Count of Tenda. On 13 June 1262, Peter married Constance, daughter and heiress of Manfred of Sicily. 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.

On James' death in 1276, the lands of the Crown of Aragon were divided amongst his two sons. The Kingdom of Aragon and the Kingdom of Valencia, along with the most of the Catalan counties, went to Peter as being the eldest son; while the Balearic Islands (constituted as the Kingdom of Majorca), the Catalan counties of Rousillon-Vallespir, Conflent and Capcir, and the territories in the Languedoc (lordship of Montpellier), went to the second son, James (James II of Majorca).