Rapidum

Auxiliary FortMauretania Caesariensis · Sour Djouab, AlgeriaBuilt 122 CE

Not standing in 117 CE

About

Roman engineers laid out this quadriburgium fort in 122 CE on the Nova Praetentura road linking Numidia to Mauretania Tingitana, roughly 100 kilometers south of Icosium. Its first garrison, the Cohors II Sardorum, watched the frontier zone between Auzia and the Chelif valley. A civilian vicus grew up around the walls and lasted until Berber raiders destroyed it under Aurelian more than a century later. Rapidum's foundation date falls five years after Trajan's death, so on 11 August 117 CE the site was still open ground.

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.