Almost contemporaneous with this fuero of Leon was that granted to Najera (Naxera) by Sancho el Mayor of Navarre (ob.
He first came into prominence at the court of Peter the Cruel, whose cause he finally deserted; he greatly distinguished himself in subsequent campaigns, during which he was twice made prisoner, by the Black Prince at Najera (1367) and by the Portuguese at Aljubarrota (1385).
John fought in the van at Najera on the 3rd of April 1367, when the English victory restored Pedro to his throne.
In 1367 he gathered a great army, entered Castile, defeated the usurper Henry of Trasta mara at the battle of Najera, and restored his ally.
The guidance of the war should have fallen into the hands of his eldest son, the victor of Poitiers and Najera, but the younger Edward had never recovered from the fatigues of his Spanish campaign; his disease having developed into a form of dropsy, he had become a confirmed invalid and could no longer take the field.