John however had become possessed of two large armies of mercenary troops of Brabantines and of freelances, who willingly executed the sanguinary orders of their chief; one corps was sent to pursue their work of ravaging the counties of the East and the Centre, the other marched towards the North under the command of the king, repulsed into Scotland the young King Alexander, who had crossed the frontier to lend his aid to the barons, and burnt down and desolated the buildings in York, Northumberland, and Cumberland. Everywhere the barons, in retiring, would lay waste their houses and fields; everywhere the king burnt down whatever he found standing; but he was still advancing, while the confederates were retreating. They at length found themselves shut up in the city of London; all their castles had fallen into the hands of the tyrant, who had made a present of them to his followers, to Satan's guards, as the people called them. The families of the confederates were at the mercy of King John. The barons resolved upon their course of action, a bitter one, that of seeking aid abroad, and accordingly sent a deputation to Philip-Augustus, proposing to give the crown of England to his son Prince Louis, if he would come to their help with an army. His arrival, it was thought, would immediately thin the ranks of King John's supporters, for they were mostly Frenchmen, and would be unwilling to fight against their own countrymen. {216} Philip-Augustus only wanted a pretext to meddle in the affairs of England. He agreed to the proposals of the barons, not, however, without requiring hostages as a guarantee of good faith; and in spite of threats from the Pope, who forbade either the father or the son to invade a fief of the Holy Church, Prince Louis set sail in the month of July with a large army, raised chiefly through the personal efforts of his wife, Blanche of Castile, a niece of King John, in whose name Louis put forth his claim to the crown of England. John's fears did not wait for the landing of the French troops; he had left Dover, and had repaired to Bristol, where the legate awaited him. Prince Louis landed at Sandwich, and, almost without striking a blow, he marched to London, which city he entered on the 2nd of June, 1216. The entire population came to meet him, and, after having offered up a prayer to St. Paul, he received homage from the barons and citizens, promising to govern them according to their laws, to protect their rights, and to restore their property to them. The satisfaction was universal: the counties surrounding London submitted willingly to Prince Louis; the oppressed inhabitants of the North revolted. A large number of John's mercenary troops deserted him, to return to their homes or to rally round the standard of France; the nobility who had become reconciled to the king, in the presence of the reverses sustained by the national cause, abandoned him to join their old friends; and, lastly, Pope Innocent III.