Early London: Prehistoric, Roman, Saxon and Norman

The buildings of a town often succeed in masking the minor physical features of its site—irregularities are levelled, brooks are hidden beneath arches and find ignominious ends in sewers; canals, quays, and terrace walls may be wholly artificial. To realise completely the original contours of the ground is often a laborious process, demanding inductive reasoning on the evidence obtained in sinking wells, in digging the foundations of the larger buildings, or in making cuttings and tunnels. Still the broader and bolder features cannot be obscured, however thick the encrusting layer of masonry may be. What, then, are these in the case of Greater London? Its site is a broad valley, along the bed of which a tidal river winds in serpentine curves as its channel widens and deepens towards the sea. On either side of this valley the ground slopes upwards, though for a while very gently, towards a hilly district, which rises, sometimes rather steeply, to a height of about 400 feet above sea-level. Towards the north this district passes into an undulating plateau, the chalky uplands of Hertfordshire; on the south it ends in a more sharply defined range, which occasionally reaches an elevation of about 800 feet above the sea—the North Downs. The upland declines a little, the valley broadens towards the sea, as the river changes into an estuary. Between the one and the other there is no very hard and fast division; the ground by the side of each is low, but as a rule by the river it is just high enough to be naturally fit for cultivation, while by the estuary it is a marsh. But as the ground becomes more salubrious, the channel becomes more shallow, and at one place, a short distance above the confluence of a tributary stream from the north—the Lea—this change in the character of the valley is a little more rapid than elsewhere.

These conditions seem to have determined the site of the city—the original nucleus of the vast aggregate of houses which forms the London of to-day. Air and water are among the prime requisites of life; no important settlement is likely to be established where the one is insalubrious, the other difficult to obtain. Thus men, in the days before systems of drainage had been devised, would shun the marshes of Essex and Kent, and, in choosing a less malarious site, would seek one where they could get water fit to be drunk, either from brooks which descended from the uplands, or from shallow wells. These conditions, as we shall see, were fulfilled in the site of ancient London; these for long years determined its limits and regulated its expansion.

Let us imagine London obliterated from the valley of the Thames; let us picture that valley as it was more than two thousand years ago, when the uplands north of the river were covered by a dense forest, and the Andreds Wald (as it was afterwards named) extended from the Sussex coast to the slopes of the Kentish Downs. We gaze, as we have said, upon a broad valley, through which the tidal Thames takes its winding course, receiving affluents from either side. These are sometimes mere brooks, sometimes rivers up which the salt water at high tide makes its way for short distances. The brooks generally rise among the marginal hills; the rivers on the northern side start far back on the undulating plateau; but on the southern the more important have cut their way completely through the range of the North Downs and are fed by streams which began their course in the valley of the Weald. Of the latter, however, probably not one is directly connected with the earliest history of London; of the former, only the Fleet, which, rising on the southern scarp of Hampstead Heath, ultimately enters the Thames near Blackfriars Bridge. But both the one and the other at later stages in the development of London may require a passing word of notice.