On Easter Monday 13 April Edward's army arrived at the gates of Chartres. The French defenders again refused battle, instead sheltering behind their fortifications, and a siege ensued. That night, the English army made camp outside Chartres in an open plain. A sudden storm materialized and lightning struck, killing several people. The temperature fell dramatically and huge hailstones along with freezing rain, began pelting the soldiers, scattering the horses. In a half-hour, the incitement and intense cold killed nearly 1,000 Englishmen and up to 6,000 horses. Among the injured English leaders was Sir Guy de Beauchamp II, the eldest son of Thomas de Beauchamp, the 11th Earl of Warwick; he would die of his injuries two weeks after. Edward was convinced the phenomenon was a sign from God against his endeavors. During the climax of the storm he is said to have dismounted from his horse and kneeled in the direction of the Cathedral of Our Lady of Chartres. He recited a vow of peace and was convinced to negotiate with the French.