{ { Infobox military conflict
| conflict = Battle of Nájera (Navarrete) | width = | partof = the Castilian Civil War | image = Battle najera froissart.jpg | image_size = 300px | alt = | caption = The Battle of Nájera from a fifteenth-century manuscript of Froissart's Chronicles. The English and Peter of Castile are on the left. | date = 3 April 1367 | place = Nájera | coordinates = | result = Victory for Peter I | combatant1 = Castilians supporting Peter Kingdom of England Duchy of Aquitaine Kingdom of Majorca Kingdom of Navarre Other Elite European mercenaries | combatant2 = Castilians supporting Henry Kingdom of FranceCrown of Aragon | commander1 = Peter of Castile Edward, the Black Prince Jean de Grailly Gaston de Foix John of Gaunt John Chandos Jean I d'Armagnac James IV of Majorca | commander2 = Henry of Trastámara Bertrand du Guesclin Alfonso of Ribagorza Tello of Castile | strength1 = Total: more than 10,000.6,000 Elite European mercenaries2,000 Aquitaine soldiers1,000 English soldiers800 Castilian soldiers500 English longbowmen300 Navarrese soldiersTroops from MajorcaHenry deserters and other Spanish followers of King Peter. | strength2 = Total: more than 4,500.2,500 Castilian soldiers1,000 Elite French mercenaries1,000 Aragonese soldiers | casualties1 = Unknown | casualties2 = Heavy losses }}
The Battle of Nájera, also known as the Battle of Navarrete''', was fought on 3 April 1367 to the northeast of Nájera, in the province of La Rioja, Castile. It was an episode of the first Castilian Civil War which confronted King Peter of Castile with his half-brother Count Henry of Trastámara who aspired to the throne; the war involved Castile in the Hundred Years' War. Castilian naval power, far superior to that of France or England, encouraged the two polities to take sides in the civil war, to gain control over the Castilian fleet.
King Peter of Castile was supported by England, Aquitaine, Majorca, Navarra and the best European mercenaries hired by the Black Prince. His rival, Count Henry, was aided by a majority of the nobility and the Christian military organizations in Castile. While neither the Kingdom of France nor the Crown of Aragon gave him official assistance, he had on his side many Aragonese Soldiers and the French free companies loyal to his lieutenant the Breton knight and French commander Bertrand du Guesclin. Although the battle ended with a resounding defeat for Henry, it had disastrous consequences for King Peter, the Prince of Wales and England.
Background
After the Treaty of Brétigny favorable to England was signed in 1360, ending the Hundred Years' War, France tried to avoid open conflict with England and tried to associate with Castile to gain an advantage. France had to find employment for the mercenaries of the great companies dedicated to pillage now that there was no war. In late 1365, Charles V of France, with the help of Pope Urban V, succeeded in diverting temporarily most of the great companies. Under the pretext of carrying on a crusade against the Moorish Kingdom of Granada, the Pope paid for an expedition to Spain. Later on, France and Aragon paid to recruit these troops for Henry's cause, removing the free companies from France and supporting the ascent to power in Castile of their favorite. The strength of the army of Henry rested primarily on these companies, groups of mercenaries that had participated in the Hundred Years' War, composed mainly of Bretons, Gascons, English and French.
The Black Prince (Edward, Prince of Wales and Duke of Aquitaine) was the main beneficiary of the peace treaty of 1362 between England and Castile that allowed Castile to keep safe maritime trade routes and in turn England kept herself safe from the large Castilian war fleet. Edward did not seem interested in prohibiting the participation of his Gascon and English subjects in the Castilian Civil War on the side of the pretender Henry, although it favoured France and was against the interests of England. Aquitaine was going through a difficult stage as the main funding sources for this traditionally poor region were the wine industry (which was depressed) and warfare. Aquitaine no longer received subsidies from England and needed other sources of revenue.