During the attacks of the pirates on the south of England the alliance between the Church and the West Saxon throne was strengthened by the common danger, and the bishops appear as patriots and statesmen. AEthelwulf was supported in his struggles with the Danes by Swithun, bishop of Winchester, and Ealhstan, bishop of Sherborne. Ealhstan was rich, and used his wealth for the defence of the kingdom; he equipped armies, joined in leading them in battle, and in 845, in conjunction with the ealdormen of Somerset and Dorset, headed the forces of his bishopric, and inflicted a severe defeat upon the invaders at the mouth of the Parret. The resistance the Danes met with from the West Saxons, which was largely due to the exertions of these bishops, delivered Wessex from invasion for twenty years. Meanwhile Lindsey and East Anglia were ravaged, Canterbury was twice sacked, and London was taken by storm. Everywhere the heathens showed special hatred to the monks and clergy; monasteries and churches were sacked and burnt, and priests were slain with the sword. These calamities were regarded as Divine judgments, and when AEthelwulf had checked the invaders he made a pilgrimage to Rome. Before he left, and after his return, he made a series of donations, which have been described as conveying a tenth part of his own estates to ecclesiastical bodies, and to various thegns, as freeing a tenth part of the folcland from all burdens except the three that fell on all lands alike, and as charging every ten hides of his land with the support of a poor man. Though these grants have nothing to do with the institution of tithes, they illustrate the sacredness that was attached to the tenth portion of property. AEthelwulf carried rich gifts to Benedict III., and while he was at Rome rebuilt the "Saxon School." This institution was supported by a yearly contribution from England, which appears to have been the origin of Peter's pence. The king probably found his youngest son Alfred at Rome, for he had sent him to Leo IV. two years before. Leo confirmed the child, and anointed him as king. The Pope did not, of course, pretend to dispose of the English crown, and probably only meant to consecrate Alfred to any kingship to which his father as head-king might appoint him. [Sidenote: Treaty of Wedmore, 878.]