The Romans

Look at where the Roman forts are in Powys and the intention is obvious. Y Gaer near Brecon, Castell Collen on the Ithon, Caersws on the Severn, Forden Gaer near Montgomery, and a scatter of smaller works between them. They are spaced roughly a day's march apart, on river crossings, along the routes running north and south through the middle of Wales.

This was a military corridor and it stayed one. In three and a half centuries Rome built no town in what is now Powys, and no villa of any consequence. Compare that with the Vale of Glamorgan, where villas are common, or with Caerwent, a full civitas capital. The difference is not accident.

The conquest

The campaigns against the Silures in the south and the Ordovices in the north and west ran from around AD 48 into the 70s and were, by Roman standards, slow and expensive. Tacitus is the main source and he is writing about his father-in-law's career, which colours it.

By the mid-70s the fort system was going in. Y Gaer was built for cavalry around AD 75. Castell Collen followed. Caersws had two forts in succession, the second holding a substantial garrison.

What they wanted

Metal, mostly, and quiet. Lead and copper came out of the hills; Llanymynech on the Shropshire border was worked for copper and shows Roman activity clearly. The road network held the whole of central Wales together and let troops move between the legionary fortresses at Chester and Caerleon without going round.

The route generally called Sarn Helen runs north to south through the western part of the county, and stretches of it are still walkable and still, in places, obviously engineered.

Occupation and abandonment

The forts were not continuously garrisoned. Several were reduced in size in the second century, which is visible in the earthworks at Castell Collen, and some were abandoned and reoccupied. That pattern suggests the province considered mid Wales settled enough to thin the garrison, then repeatedly changed its mind.

Roman activity in Powys is generally taken to fade during the fourth century.

Where to see it

Y Gaer, two and a half miles west of Brecon, has upstanding masonry including gate structures, and is the best Roman site in the county. It is on private land with permissive access; check locally.

Castell Collen at Llanyre near Llandrindod is earthworks only but the reduction of the fort is legible on the ground, which is unusual and useful.

Forden Gaer and Caersws are flatter and need more imagination. Brecknock Museum in Brecon holds material from Y Gaer.