[165] Ibid., xvi. 141.
[166] Ibid., xvi. 137.
[167] Ibid., xix. 81.
[168] Ibid., xviii. 7; xix. 173.
[169] Ibid., xviii. 66; xix. 110; xxii. 183. Malcolm, king of Scots, yielded Bamburgh, Carlisle, and Newcastle to Henry II. in 1157; and the towers at all three places were begun within a few years of this event. That at Bamburgh is mentioned in 1164.
[170] Ibid., xix. 2.
[171] See evidence brought by Mrs Armitage, Eng. Hist. Rev., xix. 443-7.
[172] Ord. Vit., iv. 1. He calls these strongholds firmamenta quaedam.
[173] A.S. Chron., sub anno.
[174] Such cross-walls, found in the larger towers, were not merely useful as partitions between the rooms. They enabled the builders to lay their floors more conveniently, as timber of sufficient scantling for so large an undivided space was obtainable with difficulty. In case of the great tower being taken by storm, the cross-wall on each floor formed a barrier to the besiegers, shutting off the tower as it did into two halves. This is well seen, for example, at Porchester.