 The north-eastern historian Robert Surtees chronicled the name changes in his "History and Antiquities of the County Palatine of Durham" but states that it is an "impossibility" to tell when the city's modern name came into being.Durham is likely to be "Gaer Weir" in Armes Prydein, derived from Brittonic "cajr" meaning "an enclosed, defensible site" (c.f.Carlisle; Welsh "caer") and the river-name "Wear".