The Roman army in Britain left a rich archaeological legacy in the form of permanently occupied installations such as legionary fortresses, auxiliary forts and frontier works. Less well-known are those field-works built by the army on campaign - marching-camps - or as part of its rigorous training regimes, namely practice-works. This volume presents a detailed study of these lesser-known field entrenchments in Wales and the Marches, a region which for a generation from the mid-first century AD became the focus of operations in southern Britain. Thereafter, complexes of practice-works in the vicinity of permanently occupied military bases illustrate the importance of the region to the training regimes of the provincial army. This volume presents a detailed description of those varied camps recorded in Wales and the Marches in the form of a gazetteer, together with plans of all accessible sites, thereby complementing those already published for most of England by the RCAHME. The camps are discussed against the background of Roman military castramentation and tactics on a wide chronological and geographical front, with specific reference to the story of early campaigning in this western region, as well as the subsequent garrisoning phase, as illustrated by a combination of literary and archaeological evidence.