Castellum Arnsburg
About
Arnsburg held the northernmost bend of the limes as it curved through the Wetterau plain, built under Domitian before 90 CE to anchor the frontier's most exposed salient. A cohort of auxiliary infantry was based here for the better part of two centuries, watching the open farmland beyond the frontier line.
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.
Sources
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 →