dunum, fort, or briva, bridge, we may perhaps reasonably infer that the town or station was founded by the Romans on a spot that had previously had no name. Possibly a similar conclusion may be justified with regard to Lindum (Lincoln), for the name is not a compound, but merely the British word lindus (modern Welsh llyn), a lake. If so, the common assumption of antiquaries that a pre-Roman town existed on the site of Lincoln is erroneous.
It is now time to speak of the names that first occur in documents written after the English became masters of Britain. Of these documents the most important for our purpose are the monastic charters from the seventh to the twelfth century, which give us English names in their correct contemporary spelling, and thereby often make their etymology quite transparent. Next in order of importance comes the Domesday Book of William the Conqueror. It is true that the vast number of names contained in this record are often badly spelt; but if we understand the principle of its orthography we can often discover with certainty what the names really were. The other sources from which we can derive information respecting the early forms of place-names are too numerous to specify.
Some of the names that first appear in these records are British, and as they date from a time when the British tongue had come nearer to modern Welsh, they are often easier to interpret than those which are found in the older sources. I have not ventured to say anything of the rivernames mentioned by Roman writers, because their etymology is very obscure. Tamēsis or Tamēsa (Thames), Trisantona (Trent), Sabrina, (Severn), Alauna (Allen and Lune), are examples of names that apparently belong to too early a stage of the language to be interpreted at present with any certainty. I may mention, however, that the name of the Dee, by Roman writers called Dēva, has been with great probability explained by Sir J. Rhŷs as meaning
