Sentiment perhaps had something to do with Mr Clark's remarkable success. There is an almost utter lack of tangible monuments of our national heroes; and therefore people who justly esteemed the labours of Alfred and his house were pleased when they were told that the mounds at Tamworth, Warwick, and elsewhere were the work of Ethelfleda, and that other mounds were the work of Edward the Elder. It did not occur to them that they were doing a great wrong to the memory of the children of Alfred in supposing them capable of building these little earthen and timber castles for their personal defence and that of their nobles, and leaving the mass of their people at the mercy of the Danes. Far other was the thought of Ethelfleda, when she and her husband built the borough of Worcester. As they expressed it in their memorable charter, it was not only for the defence of the bishop and the churches of Worcester, but "TO SHELTER ALL THE FOLK."[49] And we may be sure that the same idea lay at the founding of all the boroughs which were built by Alfred and by Edward and Ethelfleda. They were to be places where the whole countryside could take refuge during a Danish raid. The _Chronicle_ tells us in 894 how Alfred divided his forces into three parts, the duty of one part being to defend the boroughs; and from this time forth we constantly find the men of the boroughs doing good service against the Danes.[50] It was by defending and thus developing the boroughs of England that Alfred and his descendants saved England from the Danes. Thus far we have seen that all the fortifications which we know to have been built by the Anglo-Saxons were the fortifications of society and not of the individual. We have heard nothing whatever of the private castle as an institution in Saxon times; and although this evidence is only negative, it appears to us to be entitled to much more weight than has hitherto been given to it. Some writers seem to think that the private castle was a modest little thing which was content to blush unseen. This is wholly to mistake the position of the private castle in history. Such a castle is not merely a social arrangement, it is a political institution of the highest importance. Where such castles exist, we are certain to hear of some of them, sooner or later, in the pages of history.