in the north for a maximum of three months, the amount of damage he could do was limited. Mark Hagger suggests that in the words of the Anglo-Saxon Chronicle, William's Harrying of the North was "stern beyond measure" but should not be described as genocide as William was acting by the rules of his own time, not the present. Vegetius, the Latin writer, wrote his treatise De Re Militari in the fourth century about Roman warfare, and Hagger posits that this still would have provided the basis for military thinking in the eleventh century. Vegetius said, "The main and principal point in war is to secure plenty of provisions and to destroy the enemy by famine", so Hagger's conclusion is that the Harrying of the North was no worse than other similar conflicts of the time. Other historians have questioned the figures supplied by Orderic Vitalis, who was born in 1075 and would have been writing Ecclesiastical History around 55 years after the event. The figure of 100,000 deaths was perhaps used in a rhetorical sense, as the estimated population for the whole of England, based on the 1086 Domesday returns, was about 2.25 million; thus, a figure of 100,000 represented a large proportion of the entire population of the country at that time (c. 4.5%). David Horspool concludes that despite the Harrying of the North being regarded with some "shock" in Northern England for some centuries after the event, the destruction may have been exaggerated and the number of dead not as high as previously thought. Legacy In 1076 William appointed another Earl of Northumbria. This time it was Walcher, a Lotharingian, who had been appointed the first non-English Bishop of Durham in 1071. Having effectively subdued the population, William carried out a complete replacement of Anglo-Saxon leaders with Norman ones in the North. The new aristocracy in England was predominantly of Norman extraction; however, one exception was that of Alan Rufus, a trusted Breton lord, who obtained in 1069–1071 a substantial fiefdom in North Yorkshire, which the Domesday Book calls "the Hundred of the Land of Count Alan", later known as Richmondshire. Here Alan governed, as it were, his own principality: the only location held by the King in this area was Ainderby Steeple on its eastern edge, while Robert of Mortain held one village on its southern fringe; the other Norman lords were excluded, whereas Alan retained