In August 1356 the Black Prince was threatened by a larger army under John II. The English attempted to retreat but their way was blocked at Poitiers. The Black Prince tried to negotiate terms with the French, but John's army attacked the English on 19 September 1356. The English archers were able to bring down the first three assaults of the French cavalry. At the point when the English archers were running out of arrows and many were wounded or exhausted, the French king deployed his reserves, an elite force of men. It seemed that the French would win the day, however, the Gascon noble Captal de Buch managed to thwart the French by leading a flanking movement, with a small group of men, that succeeded in capturing John II, and many of his nobles. John signed a truce with Edward III, and in his absence much of the government began to collapse. John's ransom was set to two million, but John believed he was worth more than that and insisted that his ransom be raised to four million écus.