The basis of the geographical study of Domesday Book is the exact identification of place-names. Without that firm foundation all is in vain. Over 13,000 separate places are named – 13,278 in England itself, and about 140 (it is impossible to be precise) in districts now within Wales. These totals include 111 boroughs in England and one (Rhuddlan) in North Wales – see Appendix 1 (p. 336). As many as 175 places out of the grand total of 13,418 cannot be precisely located but can be assigned to particular parishes. Furthermore, 386 names out of the total (just under 3%) have not been identified, but some of these have given rise to conjecture.

Some settlements not named in Domesday Book must certainly have existed in 1086 because their names appear in pre-Domesday charters and again in documents of the twelfth and thirteenth centuries. Such, in Wiltshire, are Everleigh, Patney, Semley and Woodford. The resources of such places are presumably accounted for in the statistics recorded for named places. There are also many indications in Domesday Book itself that the total of settlements in 1086 must have been far greater than the 13,400 or so named places. In the first place, the constituent vills of a large number of manors were not separately named; then, again, some adjoining places may have been described collectively under one name; and thirdly we know from contemporary and near-contemporary sources that there were yet other places about which Domesday Book is silent.