<P> Mark Hagger suggests that in the words of the Anglo - Saxon Chronicle, William's Harrying of the North was "stern beyond measure" but we should not describe it as genocide as William was acting by the rules of his own time, not ours . Vegetius, the Latin writer, wrote his treatise De Re Militari in the fourth century about Roman warfare, and 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 . </P> <P> Other historians have questioned the figures supplied by Orderic Vitalis, who was born in 1075 and would have been writing his 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 (~ 4.5%). </P> <P> David Horspool concludes that despite the Harrying of the North, being regarded with some "shock" in the north for some centuries after the event, the destruction may not have been so extensive as once thought . </P> <P> In 1071 William appointed another Earl of Northumbria . This time it was William Walcher, a Lotharingian, who was the first non-English bishop of Durham . </P>

The main reason for the harrying of the north was to prevent another danish invasion