As much as other regions in North Africa throughout, Numidia had highly mixed ethnic population. The direct descendants of the main Berber population of ancient Numidia are very likely the olive-complexioned Kabyle people of modern Libya. Major tribal powers such as the Massylii (Maesulians) and the Masaesyli, who ruled the region of Numidia in turns from the Second to First centuries BCE, would likely have resembled the modern Kabyle people.
Black-skinned inhabitants of North Africa would have been represented in the proto-Haratin and proto-Tuareg people of North Africa, whom resided on both sides of the vast Sahara Desert. The ancient Saharan civilization of the Garamantes may have largely been of sub-Saharan origin.
In towns and cities nearer to the Mediterranean coast, Phoenician cultural influence was strong. City-states such as Carthage and Utica were founded at the beginning of the First Millenium BCE by the Phoenicians, a western Semitic people whom originated from what is now Lebanon, southern Syria and northern Palestine. Carthage, in particular, was first settled by immigrants from the city of Tyre in Lebanon and others from the island of Cyprus.
Numidia after the Third Punic War became one Rome's key allies in the western Mediterranean, providing troops for Rome's campaigns in Iberia putting down the Celtic tribes, such as the Insubres of Milan and the Boii of Bologna, who had formerly been allied with Carthage as well. When the Numidian king Micipsa died in 118 B.C., two of his sons vied to succeed to the Numidian throne. Rome, as was its practice, intervened to ensure the succession would fall to a reliable Roman ally, and divided Numidia between the two. In the course of the Roman intervention, one of the contenders, Jugurtha, bribed numerous Roman magistrates to support his claims. Jugurtha, who had served with the Romans in Iberia, fighting under the command of Gaius Marius, wasted little time before attacking his rival, ultimately capturing him and killing numerous Roman guests. This was an insult to Roman maiestas, and Rome declared war in 111 B.C.
The Senate dispatched the Roman consul Lucius Calpurnius Bestia with several legions. Bestia advanced at will throughout Numidia, but was unable to bring Jugurtha to battle, being persistently outmanoeuvred by the light cavalry which formed the heart of the Numidian army. Bestia offered to negotiate with Jugurtha, and, amidst accusations once more of bribery, concluded a peace treaty favorable to Jugurtha and his claims. Bestia was ordered home to face charges of bribery and convicted. Jugurtha himself was offered safe passage to give evidence in the trial, but inflamed matters by further bribing officials involved in the trial and organizing mob violence against his political rivals present in Rome. Jugurtha was nonetheless permitted to return to Numidia, but relations between Rome and Jugurtha were poisoned.
The Senate voted to renew against the war against Jugurtha in 109 B.C., and legions under command of consul Quintus Caecilius Metellus were once more dispatched, and once more frustrated by the hit-and-run elusiveness of the Berber horsemen. The war dragged on, and the ambitious Gaius Marius, a client of Metellus now serving as his legatus, returned to Rome and ran to succeed Metellus as consul, promising a swift end to the war. Marius, campaigning against the corruption of the ruling families, was elected and began his historic reforms of the Roman army which were undoubtedly effective, but would in time fatally destabilize the republic.
Marius returned to Numidia late in 107 B.C. and resumed the war which, despite Marius's reforms to the legions, defied quick resolution. Jugurtha still relied on the superior mobility of his horsemen to harass the legions without giving decisive battle, denying Marius the chance to demonstrate the effectiveness of his new legions. Marius' subordinate, the quaestor Lucius Cornelius Sulla, though proposed a political solution based on turning Jugurtha's ally, Bocchus I, king of Mauretania, against him. Sulla was dispatched in 106 B.C. to Mauretania, and succeeding in his mission, persuaded Bocchus to betray Jugurtha, ending the war. Bocchus was awarded several cities in western Numidia, and the rest of Numidia ruled by tribal princes dominated by Rome.
In the series Spartacus, it is far more likely that Barca is a survivor of the Roman conquest of a Carthaginian city given to the Numidians and then reconquered during the Jugurthine War, than a survivor of the conquest of Carthage itself, since the destruction of Carthage occurred approximately 70 years before the Third Servile War.
After Cato the Younger was defeated by Julius Caesar, Cato committed suicide (46 BC) in Utica, and Numidia became briefly the province of Africa Nova until Augustus restored Juba II (son of Juba I) after the Battle of Actium. Soon afterwards, in 25 BC, Juba was transferred to the throne of Mauretania, and Numidia was divided between Mauretania and the province of Africa Nova. Under Septimius Severus (193 AD), Numidia was separated from Africa Vetus, 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, Algeria) in his honor. 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 AD, which began its slow decay, accompanied by desertification. The province remained under Vandal rule, but was effectively limited to the coastal areas by Berber raids. It was restored to Roman rule after the Vandalic War, when it became part of the new praetorian prefecture of Africa.