Another important reason influenced him in this direction. France, as we have seen, was devastated by the Free Companies, who were daily growing more powerful. The Pope at Avignon trembled before them, and it was equally important to both Charles V. and the Pope to get rid of them. The two therefore joined together in hiring these companies to aid Henry. A treaty was concluded with the leaders of the companies, who were only too glad to engage on a military expedition in which they might hope for plenteous spoils. The French general, Bertrand Du Guesclin, whose fame had grown in the Breton war, was ransomed from captivity in Britany, that he might lead the Free Companies into Spain. Amongst the chiefs of the companies were many English and Gascons, who went in spite of Edward III.'s commands to the contrary. They marched over the Pyrenees into Spain, and were met at Barcelona by Henry of Trastamare.
There was no one found to take up the cause of the hated Pedro, who lost his throne without a battle, and was obliged to fly, with his two daughters, to the fortress of Corunna, and then to Bayonne. Thence he sent letters to the Black Prince, asking for his protection and aid.
We may be surprised that the Black Prince listened for a moment to the entreaties of a man whose own crimes had lost him his throne, and whose wickedness drew on him universal abhorrence. But, on the other hand, there were many things which recommended Pedro to his pity. He was the ally of England, and as a helpless fugitive asked for aid; it was always the part of a true knight to succour the distressed. Again, there was a very strong feeling in favour of the legitimate sovereign, however great his crimes might be; and we cannot wonder at one ruler feeling sympathy for the misfortunes of another. The whole situation appealed strongly to the chivalric spirit of the Prince. As a Christian knight, it was his duty, without any further thought of policy, to receive the fugitive hospitably, and help him to win back his rightful inheritance.
Some motives of policy also came in to influence him. Should an ally of France be placed on the throne of Castile, the Black Prince would be awkwardly placed in Aquitaine, with a declared enemy on one side, and a probable enemy on the other. Possibly also he indulged in some hope that he might get substantial advantages from aiding Pedro, and that he might even be able to annex the maritime province of Biscaya, with all its thriving commercial cities, whose spirit of enterprise led them to compete even with England herself.
Still the policy which could lead the Black Prince to help Pedro was not very far-sighted. He might have seen that it would be impossible to establish firmly on the throne a ruler so much hated as was Pedro. In the end the opposite party must triumph, and then he would find that he had embittered them against himself by helping their enemy. His wisest course would have been to do all in his power to secure the friendship of Henry of Trastamare; but this was opposed to all his feelings of what was due to an ally in distress.
On receiving Don Pedro's letters, the Black Prince immediately sent for Sir John Chandos and Sir William Felton, his chief advisers, and said to them, smiling, "My lords, here is great news from Spain." He then told them what he had heard, and begged them to tell him frankly what they thought he ought to do. They advised him to send a body of soldiers to bring Don Pedro safely to Bayonne, that they might learn his condition from his own mouth. Their advice pleased the Prince, and he sent Sir William Felton and a number of other knights to fetch Don Pedro. They met him at Bayonne, and treating him with the utmost honour, brought him to Bordeaux.
The Prince rode out of the town at the head of his knights to meet the fugitive king. He greeted him respectfully, and led him into the city with great courtesy. An apartment had been prepared for him, and in all things he was treated with the honour due to a reigning sovereign. Feasts and tournaments were held, and everything was done which could make him forget his miserable condition. Don Pedro on his side did all he could to attach the Prince to his interests. He had nothing but promises to give, and of these he was most liberal, promising rich gifts of money and lands to the Prince, and all his knights, if they would help his cause.
There were not wanting wise men amongst the Prince's counsellors to dissuade him from giving Don Pedro any help. They spoke to him of his secure and prosperous condition, telling him that he could want for nothing more, and that to try for more might endanger what he already possessed. They showed him the unworthiness of Pedro, how he was an enemy to religion, had oppressed his subjects, and was hated by all men. But all this made no impression on the Prince. He could not shut his eyes to Don Pedro's distress, nor forget that he had come as a fugitive to ask his help. Before deciding upon anything, however, he assembled a great council of all the barons of his duchy to ask their advice. Many of the council were eager for the enterprise, as knights in those days longed for anything which might win them honour. They agreed, however, to send ambassadors to England, to ask the advice of the King.
When the answer came back, it appeared that Edward III. and his council were clearly of the same opinion as the Prince. They advised him to aid Don Pedro with all the force at his command. The expedition was determined upon; but next arose the question of payment. The barons of Aquitaine were not willing to engage in this enterprise at their own expense. Don Pedro assured the Prince that there need be no difficulty on this head; once restored to the throne of Castile, he would have abundant treasure at his command, and would pay all the expenses of the war. The Black Prince put such trust in his word, that he made himself answerable for the expenses of the war, believing that Pedro would not fail to pay him. Chandos and Felton, however, advised the Prince to melt down some of his plate, of which he possessed an enormous quantity, for immediate expenses. Swords and coats of mail were forged at Bordeaux in preparation for the expedition.
Letters were sent to the leaders of the English Free Companies, who had accompanied Henry of Trastamare into Spain, bidding them return and aid in this expedition. It was a matter of perfect indifference to these companies for whom they fought, provided they had pay and booty enough. Though they had helped Henry of Trastamare to the throne, they were quite willing to serve under the banner of the Black Prince, and to pull down in turn the king whom they had set up.