Tomen y Mur
About
Agricola's army built this remote upland fort in 78 CE to hold down conquered Gwynedd, garrisoning roughly a thousand cavalry on an exposed spur above Llyn Trawsfynydd. Its earthworks enclosed an attached amphitheatre and parade ground, rare survivals at such an isolated post. The fort stood through Trajan's reign before Hadrianic rebuilders shrank it for a smaller infantry garrison, and Rome abandoned the site entirely around 140 CE. Norman lords later raised a castle mound directly over its ruins.
What happened here
Five hundred men, sometimes a thousand, recruited from a province rather than from citizens, and often stationed a long way from where they were raised. Cavalry units get a bigger fort and far more stabling; the smell tells you which kind you are in before the plan does. The layout copies a legionary fortress at a quarter of the size — headquarters, commander's house, granaries, barracks, a bath house usually built outside the walls because of the fire risk. Duties are patrolling, escorting, customs, and policing rather than pitched battle. After twenty-five years a man is discharged with citizenship for himself and his children, recorded on a bronze diploma he keeps for life. A village grows outside the gate within a decade.
In ancient writing
- Anonymous Roman legionary/auxiliary builders, Roman Inscriptions of Britain (RIB) RIB 421
Centurial building-stone found at Tomen-y-Mur itself, built into the fort's stone defences, recording the century of Julius Mansuetus; part of a set of 8 centurial stones documenting the Hadrianic-period rebuilding of the fort in stone.
Sources
Nearby
Roman Maps shows the empire frozen at 11 August 117 CE, the day Trajan died — its moment of greatest territorial extent. Explore the full map →