On the northwest frontier of the Roman Empire, the upland country of northern England always belonged to the military zone. Even today, anyone traversing the wild fells of Pennine or Cheviot, which form its backbone, can soon appreciate why this should be: and understanding becomes complete when imagination has pierced the dark vista of medieval forest and outlaws’ haunts and apprehended a state of affairs when the bounds between man and nature were still more loosely defined. No Anglian settler had yet begun to clear the overgrown dales for farm, hamlet and township. Man was eking out an unenviable existence between forest and fell, selecting where he could the limestone shelves whose natural drainage afforded him good pasturage and meagre tillage. Two closely related factors thus determined the political character of the country. Forest and fell not only gave cover to enemies and outlaws but at the same time prevented the growth of flourishing agricultural communities, such as were capable of developing social instincts receptive of civilization. The result was chronic unrest and potential hostility to civil government.