The Carthaginian empire's effect on the population of North Africa was a process of emulation and competition, which slowly transformed Berber society. The reaction to the growing territorial consolidation of Carthage was the formation of larger territorial entities by the Berbers. The Carthaginians named them Numidians.

The Berber-Numidians divided themselves into three kingdoms without significant influence from elsewhere: the kingdoms of . The Mauri's in modern Morocco were ruled by king Baga, but the largest of the kingdoms was Masaesyli, covering the northern half of modern Algeria, ruled by Syphax. His ruling cities were Siga (W. Algeria) and Cirta ( E. Algeria) Massyli was ruled by Gaia in a territory south of Constantine and all the way to the Tunisian coast at Gabes down to the lesser Syrtis. At this time there are contacts with the Greek world. Syphax ( Masaesyli) and Masinissa ( son of Gaia, king of Massyli) played important roles in the second Punic War. The Romans and Carthaginians realized their importance as well. Syphax and Masinissa both fought for the Romans, yet against each other, Masinissa generally losing.

Syphax eventually marries Sophonisba (daughter of a Punic general) and establishes an alliance with the Carthaginians, putting the two kingdoms formally at odds. Masinissa is eventually victorious alongside the Romans. He annexes eastern half of Masaelyi, and his territory becomes known as Numidia.