Durostorum and its vicinity were strongly affected by an invasion of the Costoboci in AD 170.
The legionary camp at Durostorum was reconstructed in the late 3rd century during the reign of either Aurelian or Diocletian.
Another unresolved question concerns which of the two civic settlements in the vicinity of Durostorum, the canabae or the vicus, was elevated in rank to municipium, or self-governing city.
Durostorum was a Roman military camp shortly before or after the beginning of the Christian era.
The garrison of Durostorum was implicated in the short-lived revolt of Regalianus, governor of Upper Pannonia (238).
In 303, however, during the joint reign of Diocletian and Maximian, a Christian named Dasius refused to accept the position (because he disapproved of the debaucheries accompanying the celebrations) and was beheaded.