After the death of Arabio, Numidia became the Roman province of Africa Nova except for a brief period when Augustus restored Juba II (son of Juba I) as a client king (29–27 BC).

Eastern Numidia was annexed in 46 BC to create a new Roman province, Africa Nova.
Western Numidia was also annexed after the death of its last king, Arabio, in 40 BC, and the two provinces were united with Tripolitana by Emperor Augustus, to create Africa Proconsularis.
In AD 40, the western portion of Africa Proconsularis, including its legionary garrison, was placed under an imperial legatus, and in effect became a separate province of Numidia, though the legatus of Numidia remained nominally subordinate to the proconsul of Africa until AD 203.
Under Septimius Severus (193 AD), Numidia was separated from Africa Proconsularis, and governed by an imperial procurator.
Under the new organization of the empire by Diocletian, Numidia was divided in two provinces: the north became Numidia Cirtensis, with capital at Cirta, while the south, which included the Aurès Mountains and was threatened by raids, became Numidia Militiana, "Military Numidia", with capital at the legionary base of Lambaesis.
Subsequently, however, Emperor Constantine the Great reunited the two provinces in a single one, administered from Cirta, which was now renamed Constantina (modern Constantine) in his honour.
Its governor was raised to the rank of consularis in 320, and the province remained one of the seven provinces of the diocese of Africa until the invasion of the Vandals in 428, which began its slow decay, accompanied by desertification.
It was restored to Roman rule after the Vandalic War, when it became part of the new praetorian prefecture of Africa.
After the death of Arabio, Numidia became the Roman province of Africa Nova except for a brief period when Augustus restored Juba II (son of Juba I) as a client king (29–27 BC).
Eastern Numidia was annexed in 46 BC to create a new Roman province, Africa Nova. Western Numidia was also annexed after the death of its last king, Arabio, in 40 BC, and the two provinces were united with Tripolitana by Emperor Augustus, to create Africa Proconsularis. In AD 40, the western portion of Africa Proconsularis, including its legionary garrison, was placed under an imperial legatus, and in effect became a separate province of Numidia, though the legatus of Numidia remained nominally subordinate to the proconsul of Africa until AD 203. Under Septimius Severus (193 AD), Numidia was separated from Africa Proconsularis, and governed by an imperial procurator. Under the new organization of the empire by Diocletian, Numidia was divided in two provinces: the north became Numidia Cirtensis, with capital at Cirta, while the south, which included the Aurès Mountains and was threatened by raids, became Numidia Militiana, "Military Numidia", with capital at the legionary base of Lambaesis. Subsequently, however, Emperor Constantine the Great reunited the two provinces in a single one, administered from Cirta, which was now renamed Constantina (modern Constantine) in his honour. Its governor was raised to the rank of consularis in 320, and the province remained one of the seven provinces of the diocese of Africa until the invasion of the Vandals in 428, which began its slow decay, accompanied by desertification. It was restored to Roman rule after the Vandalic War, when it became part of the new praetorian prefecture of Africa.
Numidia