At the
411 Conference of Carthage, which saw the
Catholics and
Donatists, debate, the town was represented by the Catholic Justus episcopus Nicibensis, who did not have Donatist counterpart.
Finally a
Byzantineinscription discovered in the region of
N'Gaous and dating back to 581 or 582 shows the name Colombo: according to the same author this Columbus may be the bishop referred to in some letters from
Gregory the Great written at the beginning of the 7th century who was appointed to investigate Massimiano bishop of
Pudenziana, accused by his deacons of being bribed by
Donatists.