"The history of the Castle has no beginning so far as we know. The furthest records or surmises or inferences simply accept it as existing. Some of these--guesses, let us call them--seem to show that there was some sort of structure there when the Romans came, therefore it must have been a place of importance in Druid times--if indeed that was the beginning. Naturally the Romans accepted it, as they did everything of the kind that was, or might be, useful. The change is shown or inferred in the name Castra. It was the highest protected ground, and so naturally became the most important of their camps. A study of the map will show you that it must have been a most important centre. It both protected the advances already made to the north, and helped to dominate the sea coast. It sheltered the western marches, beyond which lay savage Wales--and danger. It provided a means of getting to the Severn, round which lay the great Roman roads then coming into existence, and made possible the great waterway to the heart of England--through the Severn and its tributaries. It brought the east and the west together by the swiftest and easiest ways known to those times. And, finally, it provided means of descent on London and all the expanse of country watered by the Thames. "With such a centre, already known and organised, we can easily see that each fresh wave of invasion--the Angles, the Saxons, the Danes, and the Normans--found it a desirable possession and so ensured its upholding. In the earlier centuries it was merely a vantage ground. But when the victorious Romans brought with them the heavy solid fortifications impregnable to the weapons of the time, its commanding position alone ensured its adequate building and equipment. Then it was that the fortified camp of the Caesars developed into the castle of the king. As we are as yet ignorant of the names of the first kings of Mercia, no historian has been able to guess which of them made it his ultimate defence; and I suppose we shall never know now. In process of time, as the arts of war developed, it increased in size and strength, and although recorded details are lacking, the history is written not merely in the stone of its building, but is inferred in the changes of structure. Then the sweeping changes which followed the Norman Conquest wiped out all lesser records than its own. To-day we must accept it as one of the earliest castles of the Conquest, probably not later than the time of Henry I. Roman and Norman were both wise in their retention of places of approved strength or utility. So it was that these surrounding heights, already established and to a certain extent proved, were retained. Indeed, such characteristics as already pertained to them were preserved, and to-day afford to us lessons regarding things which have themselves long since passed away.