In 853 a Viking force entrenched itself in Thanet and defeated an attempt of the Kentishmen to dislodge them, but then abandoned the isle and sailed to fields where plunder was more easily gained than among the obstinate Englishmen. But in 854 they were again in England, and wintered in Sheppey; and Aethelwulf chose the next year to go on pilgrimage to Rome! His son Aethelbald seized the opportunity to practically oust his father--not without some justification in Aethelwulf’s ill-timed religious enthusiasm. When the king came back he was content to acknowledge his son as king in Wessex, keeping only Kent, Sussex, and Essex for himself. The result of this dissension was, of course, a serious weakening of the suzerain power of Wessex. Aethelwulf died in 858. His successor, the rebellious Aethelbald, reigned only two and a half years, and was then succeeded by his brother Aethelbert, who held the sceptre for six years. There were sporadic Viking raids at intervals after 855, but it was not until 860 that the danger again became serious. In that year a large Viking fleet, under a chief named Vœlund, was bribed to depart from France by the wretched Charles the Bald, and forthwith turned its dragon prows towards England. It sailed up Southampton Water, and its crews landed and marched upon Winchester. Its walls were ruinous, and it was taken and sacked; but immediately afterwards the Vikings were attacked by the men of Berkshire and Hampshire, under the Ealdormen Aethelwulf and Osric, and totally routed. This success of a hurried assemblage of country-folk shows that the military efficiency of the Wessex peasants was not to be despised. For some five years the Northmen left England alone, but in 865 a great horde descended on Kent. An attempt was made to buy them off, and an armistice was declared, but they broke the truce and ravaged eastern Kent before assistance could be brought from Wessex. They then settled down for the winter in Thanet. Next spring King Aethelbert died, and was succeeded by his brother Aethelred I. The success of 865 had apparently determined the whole Viking swarm in France to come over to England. Whether their leaders had any definite design of settlement it is impossible to ascertain, but the deliberation of their movements shows that they were carefully calculated. The people of Wessex had shown themselves to be warlike and patriotic, and its kings by no means despicable opponents. So the ‘Great Army’ poured into East Anglia, where they desisted from plunder after receiving a heavy subsidy, but wintered in the unhappy country and swept up its horses, so as to be able to move swiftly.