Sometimes the light thrown by Scandinavian place-names on the Anglo- Saxon landscape only seems to offer a pale reflection of reality or perhaps more exactly a negative view of it, as in the map of England and southern Scotland (Figure 4.1), on which small open circles, black circles and open squares show the presence of settlements with names ending in the elements -bý, -thorp or hybrid names in -tūn. It is known that such names in the Danelaw were coined in the Viking period, and areas north and east of the Danelaw boundary from which such symbols are practically absent tend either to be on the land above 250 metres in height (hatched) or in the marshy areas (stippled). These areas point to the unspoilt survival to the later Anglo-Saxon and Anglo-Norman periods of vast tracts of mountainous and marshy land.

When we close in to take a look at just a small part of the Danelaw, for example Kenneth Cameron's map of the distribution of the býs in the Lincolnshire Wolds (Figure 4.2), it becomes possible to refine the picture presented by studying the way in which the black circles representing býs form patterns that can sometimes be explained by the underlying topography, as when the dots in the northern section of the map lie along the prehistoric trackways almost like strings of beads on two necklaces running from the Humber roughly parallel to each other towards the south-east.