Here, as in many other conjectures concerning early history or pre-history, one is convinced of that safe rule which, in Europe at least, bids us never exaggerate the changes achieved by the last few centuries or the contrast between recorded and unrecorded things. The tendency of most modern history in this country has been to exaggerate such changes and such contrasts. In the greater part of modern popular history care is taken to emphasise the difference between the Middle and Dark Ages and the last few centuries. The forests of England are represented as impassable, or nearly so; the numbers of the population are grossly underestimated; the towns which have had a continuous municipal existence of 1500 years are represented as villages. The same spirit would tend to make of the Thames Valley in the Dark and Middle Ages a very different landscape from that which we see to-day. The floods were indeed more common and the passage of the river somewhat more difficult; cultivation did not everywhere approach the banks as it does now; and in two or three spots where there has been a great development of modern building, notably at Reading, and, of course, in London, the banks have been artificially strengthened. But with these exceptions it may be confidently asserted that no belt of densely inhabited landscape in England has changed so little in its natural features as the Thames Valley. There are dozens of reaches upon the upper Thames where little is in sight save the willows, the meadows, and a village church tower, which present exactly the same aspect to-day as they did when that church was first built. You might put a man of the fifteenth century on to the water below St. John's Lock, and, until he came to Buscot Lock, he would hardly know that he had passed into a time other than his own. The same steeple of Lechlade would stand as a permanent landmark beyond the fields, and, a long way off, the same church of Eaton Hastings, which he had known, would show above the trees.