"custodiam _turris Gloc' cum toto castello_," etc., etc.... "per eandem firmam quam reddere solebat comes Milo pater ejus tempore H. R. avi mei;"[948] while Robert of Torigny speaks, independently, of "discordia quæ erat inter regem Anglorum Henricum et Rogerium, filium Milonis de Gloecestria, propter _turrim_ Gloecestrie."[949] The "tower" of Gloucester is also referred to in the Pipe-Roll of 1156,[950] and in the Cartulary of Gloucester Abbey.[951] The importance of its mention lies in the fact that it establishes the character of Gloucester Castle, and proves that what the leading authority has written on the subject is entirely erroneous. Mr. G. T. Clark, in his great work on our castles, refers thus to Gloucester:— "The castle of Gloucester ... was the base of all extended operations in South Wales. Here the kings of England often held their court, and here their troops were mustered. Brichtric had a castle at Gloucester, _but his mound has long been removed, and with it all traces of the Norman building_."[952] In another place he goes further still:— "Gloucester, a royal castle, stood on the Severn bank, at one angle of the Roman city. _It had a mound and a shell-keep, now utterly levelled_, and the site partially built over. It was the muster-place and starting-point for expeditions against South Wales, and the not infrequent residence of the Norman sovereigns."[953] It may seem rash, in the teeth of these assertions, to maintain that this mound and its shell-keep are alike imaginary, but the word "turris" proves the fact. For, as Mr. Clark himself observes with perfect truth, "in the convention between Stephen and Henry of Anjou (1153) the distinction is drawn between '_Turris_ Londinensis et _Mota_ de Windesorâ,' London having a square keep or tower, and Windsor a shell-keep upon a mound."[954] So the keep of Gloucester, being a "turris" and not a "mota," was clearly "a square tower" and not "a shell-keep upon a mound." The fact is that Mr. Clark's assertions would seem to be a guess based on the hypothesis, itself (as could be shown) untenable, that "Brichtric had a castle at Gloucester." Assuming from this the existence of a mound, he must further have assumed that the Normans had crowned it, as elsewhere, with a shell-keep. But the true character of this great fortress is now determined. Two examples of the double style shall now be adduced from castles outside England. In Normandy we have an entry, in 1180, referring to expenditure "in operationibus domorum _turris et castri_," etc., at Caen;[955] in Ireland the grant of Dublin Castle to Hugh de Laci (1172) is thus related in the so-called poem of Matthew Regan (ll. 2713-2716):— "Li riche rei ad dune baillé Dyvelin en garde la cité _E la chastel e le dongun_ A Huge de Laci le barun." The phrase, it will be seen, corresponds exactly with those employed to describe the castles of Carlisle and Appleby, at the same period:—