Celtic toponymy from Brythonic *"crüg" 'hill' (Irish "cruach") From tribal name "Dumnonii" or "Dumnones", from Celtic *"dumno-" 'deep', 'world' From Celtic *"dubr-" 'water', *"dubrās" 'waters' (Welsh "dwfr"; Breton "dour") First element is possibly "dun", ' hill fort' (Welsh ddin, 'fort'). First element from Celtic *"duro-" 'fort'; in "Dūrobrīvae", Celtic *"brīwa" 'bridge' Possibly derived from Brythonic *"iska", 'water, fish' and *"leith", 'damp, wet'. From Celtic *"iska" 'water' (Irish "uisce"); second element in "Isca Dumnoniorum" (Exeter) is a tribal name (see "Devon") From Brythonic *"lēd-" [from Celtic *"leito-"] + *"rïd-" [from Celtic *"(φ)ritu-"] = "Grey Ford" From Celtic *"lindo-" 'pool' + Latin "colonia" 'colony'
Isca Dumnoniorum building in the fortress not of timber was a stone-built military bathhouse. The water for the bathhouse was supplied by a natural spring via an aqueduct which entered the fortress through the rear gate (). The excavations revealed the hot room () and part of the warm room (). The bathhouse was also supplied with an external exercise yard (), one corner of which was a cockfighting pit. The legion had formed part of the Claudian invasion of Britain in 43, under the command of the future emperor Vespasian. Vespasian led campaigns against both the Durotriges and Dumnonii. The presence