My South London extends from Battersea in the west to Greenwich in the east, and from the river on the north to the first rising ground on the south. This rising ground, a gentle ascent, the beginning of the Surrey hills, can still be observed on the high roads of the south--Clapham, Brixton, Camberwell. It now occupies the place of what was formerly a low cliff, from ten to thirty or forty feet high, overhanging the broad level, and corresponding to those cliffs on the other side of the river, which closed in on either side of Walbrook and made the foundation of London possible. If we draw a straight line from the mouth of the Wandle on the west to the mouth of the Ravensbourne on the east, we shall, roughly speaking, indicate the southern boundary of our district; unless, as we may very well do, we include Greenwich as well. The whole of this region constitutes the Great South Marsh: there is no rising ground, or hillock, or encroaching cliff over the whole of this flat expanse. Before the river was embanked it was one unbroken marsh: for eight miles in length by a varying breadth of about two or two and a half miles, the tidal stream twice in the twenty-four hours submerged this space. Here and there lay islets or eyots, created, as the centuries crept on, by the gradual accumulation of branches, roots, reeds and rubbish, till they rose a few inches above high water; the spring-tide covered them--sometimes swept them away--then others began to form. In later times, after the work of embankment had been commenced, these islets became permanent, and were afterwards known as Battersea, Bermondsey, Rotherhithe, Lambhithe, Newington, Kennington. Even then, for many a long year, they were but little areas rising a foot or two above the level, covered with sedge, reeds, and tufts of coarse grass, hardly distinguishable from the rest of the ground around them. Before the construction of the river wall, no trees stood upon this morass, no flowers of the field flourished there, no thorns and bushes grew, no cattle pastured there; the wild deer were afraid of it: there were no creatures of the land upon it. On the south side rose the cliff of clay and sand, continually falling and continually receding before the encroaching tide; on the north side ran the river; beyond the river the cliff stood up above the water's edge, where the tiny stream, afterwards named from the Wall, leaped bright and sparkling into the rolling flood. No man could live upon that marsh: its breath after sunset and in the night was pestilential. [Illustration: View from Southwark Marsh in Prehistoric Times.]