But when the Prince had been a month at Burgos, he began to be impatient to return to his own dominions. He had as yet received none of the promised money from Pedro, in payment of the expenses of the campaign. He therefore told the King that he was anxious to return and disband his army, and demanded the money to pay his troops. Pedro said that he fully intended to pay as he had promised, but that at that moment he had no money. At Seville, however, he had a large treasure, and if the Black Prince would allow him to depart, he would go and fetch it. Meanwhile, he proposed that the Prince and his army should quarter themselves in the fertile country round Valladolid. He promised to bring him the money at Whitsuntide. The Black Prince, himself always honest and straightforward, was ever ready to trust in others, and easily agreed to do as Pedro proposed. It was a fatal step; for once away from Pedro's side, he lost all hold upon him. The Prince's army established itself round Valladolid, and the Free Companies supported themselves by pillaging the peasants. The summer drew on, and the army began to suffer from the hot climate. Disease broke out in the camp, and it is said that four out of every five of the soldiers died. Whitsuntide came, but brought no money from Pedro. The Prince grew more and more uneasy. At last he sent three of his knights to the Spanish King, to ask him why he did not keep his promise. To them Pedro professed great sorrow that he had not been able to send the money sooner, and repeated his promises; but said that he could not drain his people of money, and, above all, he could not send any money as long as the Free Companies were in the country; for they did so much harm. If the Prince would send the companies away, and only let some of his knights remain, he would soon send the money. When this answer was brought back to the Prince he became very sad; for he saw clearly that Don Pedro did not mean to keep his promises. His own health was failing; he had been attacked by an illness which was never to leave him. Bad news was brought him from Bordeaux. The Princess wrote that Henry of Trastamare was attacking the frontiers of Aquitaine. His army was rapidly dwindling before his eyes. Man after man died from the effects of the climate. There was nothing for it but to return to Bordeaux. In sadness he gathered his troops together, and felt thankful that he was allowed to pass peaceably through Navarre and the dangerous passes of the Pyrenees.