The topographical features of the site that was to become Norfolk's county town were such as to encourage settlement. Around it lay a highly fertile soil, another result of valley formation. By the early Saxon period the sea had receded to its present level, but the continuing free-flow of the tide kept parts of Norwich's site marshy for several centuries, making the medieval river wider and shallower than today. Opposite, on the northern bank, another ridge continued the direction along Fybriggate.
Crossroads tend to be magnets for settlement.
Despite the legendary associations of Norwich castle, there is no evidence of such a fortification in that locale until the Normans. By circa 500 A.D., there is evidence of occupation in the area, at least on the northern bank of the Wensum. The bounds of settlement north of the Wensum remained confined, throughout the medieval period, to the area defined by the gravel terrace. These may have been only minor settlements. Archaeological remains suggest this was contemporary with, but larger than, the western settlement.