In the year of our Lord's incarnation 851, which was the third after the birth of king Alfred, Ceorl, earl of Devon, fought with the men of Devon against the pagans at a place called Wicgambeorg;[89] and the Christians gained the victory; and that same year the pagans first wintered in the island called Sheppey, which means the Sheep-isle, and is situated in the river Thames between Essex and Kent, but is nearer to Kent than to Essex; it has in it a fine monastery.[90] The same year also a great army of the pagans came with three hundred and fifty ships to the mouth of the river Thames, and sacked Dorobernia,[91] which is the city of the Cantuarians, and also the city of London, which lies on the north bank of the river Thames, on the confines of Essex and Middlesex; but yet that city belongs in truth to Essex; and they put to flight Berthwulf, king of Mercia, with all the army, which he had led out to oppose them. After these things, the aforesaid pagan host went into Surrey, which is a district situated on the south bank of the river Thames, and to the west of Kent. And Ethelwulf, king of the West-Saxons, and his son Ethelbald, with all their army, fought a long time against them at a place called Ac-lea,[92] i.e. the Oak-plain, and there, after a lengthened battle, which was fought with much bravery on both sides, the greater part of the pagan multitude was destroyed and cut to pieces, so that we never heard of their being so defeated, either before or since, in any country, in one day; and the Christians gained an honourable victory, and were triumphant over their graves. In the same year king Athelstan, son of king Ethelwulf, and earl Ealhere slew a large army of pagans in Kent, at a place called Sandwich, and took nine ships of their fleet; the others escaped by flight. In the year of our Lord's incarnation 853, which was the fifth of king Alfred, Burhred, king of the Mercians, sent messengers, and prayed Ethelwulf, king of the West-Saxons, to come and help him in reducing the midland Britons, who dwell between Mercia and the western sea, and who struggled against him most immoderately. So without delay, king Ethelwulf, having received the embassy, moved his army, and advanced with king Burhred against Britain,[93] and immediately, on entering that country, he began to ravage it; and having reduced it under subjection to king Burhred, he returned home.