The chapters on Saxon and Danish earthworks in the present volume were written before the appearance of his book, though the results arrived at are only slightly different. In Chapter V. An effort is made to trace the first appearance of the private castle in European history. The private castle is an institution which is often care lessly supposed to have existed from time immemorial. The writer contends that it only appears after the establishment of the feudal system. The favourable reception given by archaeologists to the paper read before the Scottish Society led the writer to follow up this interesting subject, and to make a closer study of the motte-castles of Wales, Scotland, and Ireland. The book now offered is the fruit of eleven years of further research. The result of the inquiry is to establish the theory advanced in that earlier paper, that these castles, in the British Islands, are in every case of Norman origin.