However , the Romans withdrew from the area a few decades later during the Crisis of the Third Century .
A permanent Roman garrison was established during the reign of Septimius Severus , and the emperor may have visited the settlement around AD 202 .
The Roman withdrew from the area a few decades later during the Crisis of the Third Century .
A permanent Roman garrison was established during the reign of Septimius Severus , and the emperor may have visited the settlement around AD 202 .