Cheffia

Cheffia occupies a valley in northeastern Algeria. The valley extends roughly fifteen kilometres from north to south and five kilometres across. Its cultivated plateau of Sidi-Bou-Aoun, marked by large stones, divides the land into two basins and gives the small district a distinct internal structure. Beneath the later settlement lie the remains of Roman Thullium in Numidia. The surrounding valley also contains burial grounds considered Libyan necropolises, several of them bearing Libyco-Berber inscriptions. These graves and scattered ruins show that the locality held importance before medieval settlement.

Christian institutions arrived slowly. Thullium's first recorded bishop belongs to the end of the fifth century, and another bishop from the see attended the Council of Carthage in 525. The late date is significant: it shows that episcopal organization came after the town's earlier urban life.