The Anglo-Saxons: A History of the Beginnings of England

by Marc Morris

The most remarkable part of the Burghal Hidage is its second half, which reveals the king’s scheme for keeping his fortresses fully manned. After the list of burhs comes the formula by which their allocations of hides were calculated, based on the number of men needed to man the walls. ‘For the maintenance and defence of an acre’s breadth of wall,’ it states, ‘sixteen hides are required. If every hide is represented by one man, then every pole [5½ yards] can be manned by four men.’ Put more simply, one man was expected to defend just over four feet of wall. Because we have the output data of this equation – the number of hides allocated to each burh – we can work out the wall-lengths the author had used as the basis of his calculations. And, remarkably, there is a fairly close correspondence between the figures he used and the dimensions of surviving burhs. Wareham’s allocation of 1,600 hides, for example, implies it had 2,200 yards of wall to defend, and the surviving circuit of defences extends for about 2,180 yards. There is a similar close correlation at Winchester. The city’s assessment of 2,400 hides was based on a perimeter reckoned at 3,300 yards, and the length of Winchester’s Roman walls as measured today is 3,318 yards.