_The English come to London._--It is generally held that London was walled towards the end of the fourth century. Mr. Green suggests, indeed, that it and the fortresses of the Saxon shore mentioned in the _Notitia_ were fortified as a provision against the attacks of Picts and Saxons. The need for such protection was soon made evident, for the only event chronicled in regard to London during the early period of the English Conquest is that in 457, after the battle of "Creganford," the Britons fled from Kent to London. Then comes silence for a century and a half, until 604, when it is told how Mellitus, a companion of St. Augustine, was sent to preach to the East Saxons, whose king, Sebert, a nephew of Ethelbert, gave Mellitus a bishop's stool in London. Although there is no definite statement as to when the English entered the wonderful walled city that was to become their capital, yet by following converging lines of evidence we may determine the point of time with almost certain accuracy. We have for this purpose (1) the chronicle of the conquests of the several branches of the Angle and Saxon peoples; (2) the British accounts and legends; (3) the traditional history, as given by such writers as Henry of Huntingdon and William of Malmesbury, of the succession of kings in the "Heptarchy." (1) Up to _c._ 500 we have the conquests of Kent, Sussex, and Wessex, the first two confined to the present county limits, and the last with its centre at Winchester, only reaching Sarum in 552, and striking north-east to Aylesbury and Bedford in 571. According to Dr. Guest and Mr. Green, the great fortress of London and its bridge up to this time barred the natural approach of the invaders up the Thames valley. Another horde, who became the East Saxons, had, in the meantime, effected a settlement in the county yet called after them. These reached Verulam about 560, for Gildas (_c._ 516 to 570) deplores the loss of that city, but says nothing of London. It was by the Wessex advance of 571 that the frontier between itself and Essex was defined; and as London, which is so near the boundary line, belonged (at a later time at least) to the latter, we may suppose that it had already before 571 been taken possession of by the East Saxons. Again, the men of Kent, in 568, attempted to press on over Surrey, but were beaten back by the men of Wessex. Mr. Green well suggests that this attempted advance was an immediate consequence of the reduction of London, which had hitherto held Kent back. (2) The British legends given by Geoffrey of Monmouth refer to several incidents in London during the sixth century, culminating in the flight of Theon, its archbishop, in the second half of the century--Hovenden says in 586.