Roman
name was Mancunium, which would easily glide into Mancunceaster. In the
_English Chronicle_ it is only once mentioned, and then as
Mameceaster--a form explained by the alternative Mamucium in the
Itinerary, which would naturally become Mamue ceaster. Colchester of
course represents Colonia, corrupted first into Coln ceaster, and so
through Col ceaster into its present form. Porchester in Hants is
Portus Magnus; Dorchester is Durnovaria, and then Dorn ceaster.
Grantchester, Godmanchester, Chesterfield, Woodchester, and many others
help us to trace the line across the map of England, to the most
western limit of all at Ilchester, anciently Ischalis, though the
intermediate form of Givel ceaster is certainly an odd one.

Besides these Chesters of the regular order, there are several curious
outlying instances in Durham and Northumberland, and along the Roman
Wall, islanded, as it were, beyond the intermediate belt of Casters.
Such are Lanchester in Durham, which maybe compared with the more
familiar Lancaster; Great Chesters in Northumberland, Ebchester on the
northern Watling Street, and a dozen more. How to account for these is
rather a puzzle. Perhaps the Casters may be mainly due to Danish
influence (which is the common explanation), and it is known that the
Danes spread but sparingly to the north of the Tees. However, this
rough solution of the problem proves too much: for how then can we have
a still softer form in Danish Leicester itself? Probably we shall be
nearer the truth if we say that these are late names; for
Northumberland was a desert long after the great harrying by William
the Conqueror; and by the time it was repeopled, Chester had become the
recognised English form, so that it would naturally be employed by the
new occupants of the districts about the Wall.

No name in Britain, however, is more interesting than that of
Rochester, which admirably shows us how so many other Roman names have
acquired a delusively English form, or have been mistaken for memorials
of the English conquest. The Roman town was known as Durobrivae, which
does not in the least resemble Rochester; and what is more, Baeda
distinctly tells us that Justus, the first bishop of the West Kentish
see, was consecrated 'in the city of Dorubrevi, which the English call
Hrofaes ceaster, from one of its former masters, by name Hrof.' If this
were all we knew about it, we should be told that Baeda clearly
described the town as being ca