TheFossa Regia, also called theFosse Scipio, was the first part of theLimes Africanus to be built in RomanAfrica. It was used to divide theBerber kingdom ofNumidia from the territory of Carthage that was conquered by the Romans in the second century BC.
It was an irregular ditch "fromThabraca on the northern coast toThaenae on the south-eastern coast".[1]
The Fossa was dug by the Romans after their final conquest of Carthage at the end of theThird Punic War in 146 BC. The construction's primary purpose was administrative, not military. It delineated the limits of the newly createdRoman province of Africa marking the border between theRoman Republic and its then allyNumidia.[2]
After the end ofCaesar's Civil War in 46 BC, the western part of theFossa regia served as the boundary between the province ofNova Africa, to its west, and the province ofAfrica Vetus to its east. Even after these two provinces were merged intoProconsular Africa in 27 BC, the ditch continued to be maintained as late as the year 74 AD underVespasian as shown by many stone marker posts that have been found.
Ea pars quem Africam appellavimus dividitur in duas provincias, veterem ac novam, discretas fossa inter Africanum sequentem et reges Thenas usque perducta. — Plinius,Historia Naturalis, V, 25 (AD 77)
(The region that we call Africa is divided in two provinces, old and new, by a "fossa" (ditch) stretching in Africa from Thenas (near Sfax) to the Thabarca area).
East ofFossa regia there was fullLatinization of the local society afterTrajan. UnderTheodosius that area[3] was fully Romanized with one third of the population made of Italic colonists and their descendants, according to historianTheodore Mommsen. The other two thirds wereRomanized Berbers, all Christians and nearly all Latin speaking.