Edward the Black Prince compelling Peter of Castile to flee from his kingdom, and in setting up his bastard brother, Henry of Trastámara, as king in his stead. Peter, who was in alliance with Edward III, sent messengers to the Black Prince asking his help, and on receiving a gracious answer at Corunna, set out at once, and arrived at Bayonne with his son and his three daughters. The prince met him at Capbreton, and rode with him to Bordeaux. Many of the prince's lords, both English and Gascon, were unwilling that he should espouse Peter's cause, but he declared that it was not
Edward the Black Prince already warned his father of the intentions of the French king, but there was evidently a party at Edward's court that was jealous of his power, and his warnings were slighted. In April 1369, however, war was declared. Edward sent the Earls of Cambridge and Pembroke to his assistance, and Sir Robert Knolles, who now again took service with, him, added much to his strength. The war in Aquitaine was desultory, and, though the English maintained their ground fairly in the field, every day that it was prolonged weakened their hold on the country. On 1 January 1370 the Black