Phasis

Auxiliary FortCappadocia · near Poti, Georgia (site traditionally called Najikhuri)Built 64 CE

About

Roman troops built this fort where the Phasis River met the Black Sea, part of the garrison network Rome planted along the Colchian coast from the 60s CE onward. Arrian described digging a defensive ditch around the base during his 131 CE tour of the Pontic garrisons. Local tradition places its remains at a site called Najikhuri, east of modern Poti, though the river's shifting course has obscured the footprint. The post marked Rome's furthest garrison up the Caucasus coast.

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.