Even to-day, and in an England that has lost hold of her past more than has any rival nation, Windsor seems to the passer-by to possess a meaning. That hill of stones, sharp though most of its modern outlines are, set upon another hill for a pedestal, gives, even to a modern patriot, a hint of history; and when it is seen from up-stream, showing its only noble part, where the Middle Ages still linger, it has an aspect almost approaching majesty. The creator of Windsor was the Conqueror. The artificial mound on which the Round Tower stands may or may not be pre-historic. The slopes of the hill were inhabited, like nearly all our English sites, by the Romans, and by the savages before and after the Romans; but the welter of the Saxon dark ages did not use this abrupt elevation for a stronghold. What military reasoning led William of Falaise to discern it at once and there to build his keep? In order to answer that question let us consider what other points in the valley were at his disposal. Reading we have discussed. The chalk spurs in the gorge by Goring and Pangbourne are not isolated (as is that of Chateau Gaillard, for instance), and are dominated by the neighbouring heights. The escarpment opposite Henley offered a good site for an eleventh-century castle--but the steep cliff of Windsor had this advantage beyond all the others--that it was at exactly the right distance from London. Windsor is the warden of the capital. If the reader will look at a modern geological map, he will see from Wallingford to Bray a great belt of chalk in which the trench of the Thames is carved. Alluvials and gravels naturally flank the stream, but chalk is the ground rock of the whole. To the west and to the east of this belt he will notice two curious isolated patches, detached from the main body of the chalk. That to the west forms the twin height of the Sinodun Hills, rising abruptly out of the green sand; that to the east is the knoll of Windsor, rising abruptly out of the thick and damp clay. It is a singular and unique patch, almost exactly round, and as a result of some process at which geology can hardly guess the circle is bisected by the river. If ever the chalk of the north bank rose high it has, in some manner, been worn down. That on the south bank remains in a steep cliff with which everyone who uses the river is familiar. It was the summit of this chalk hill piercing through the clays that the Conqueror noted for his purpose, and he was, to repeat, determined (we must presume) by the distance from London.