Numidia, the name given in ancient times to a tract of country in the north of Africa, extending along the Mediterranean from the confines of Mauretania to those of the Roman province to Africa. When the Romans first came into collision with Carthage in the 3rd century B.C., the name was applied to the whole country from the river Mulucha (now the Muluya), about too m. W. of Oran, to the frontier of the Carthaginian territory, which nearly coincided with the modern regency of Tunis. It is in this sense that the name Numidia is used by Polybius and all historians down to the close of the Roman republic. The Numidians, as thus defined, were divided into two great tribes, - the lvlassyli on the east, and the Massaesyli on the west - the limit between the two being the river Ampsaga, which enters the sea to the west of the promontory called Tretum, now known as the Seven Capes. At the time of the second Punic War the eastern tribe was governed by Massinissa, who took the side of the Romans in the contest, while Syphax his rival, king of the Massaesyli, supported the Carthaginians. At the end of the war the victorious Romans confiscated the dominions of Syphax, and gave them to Massinissa, whose sway extended from the frontier of Mauretania to the boundary of the Carthaginian territory, and also south and east as far as the Cyrenaica (Appian, Punica, 106), so that the Numidian kingdom entirely surrounded Carthage except towards the sea. Massinissa, who reached a great age, retained the whole of these dominions till his death in 148 B.C. and was succeeded in them by his son Micipsa, who died in 118. For the war with Rome which followed the death of Micipsa see Jugurtha.
After the death of Jugurtha as a captive at Rome in 106, the western part of his dominions was added to those of Bocchus, king of Mauretania, while the remainder (excluding perhaps the territory towards Cyrene) continued to be governed by native princes until the civil war between Caesar and Pompey, in which Juba I., then king of Numidia, who had espoused the cause of the Pompeians, was defeated by Caesar, and put an end to his own life (46 B.C.). Numidia, in the more restricted sense which it had now acquired, became for a short time a Roman province under the title of Africa Nova, but in the settlement of affairs after the battle of Actium it was restored to Juba II. (son of Juba I.), who had acquired the favour of Augustus. Soon afterwards, in 25 B.C., Juba was transferred to the throne of Mauretania, including the whole western portion of the ancient Numidian monarchy as far as the river Ampsaga, while the eastern part was added to the province of Africa, i.e. that part which had been called Africa Nova before it was given to Juba. It retained the official title, though it may also have been known as Numidia; together with Africa Vetus it was governed by a proconsul, and was the only senatorial province in which a legion was permanently stationed, under the orders of the senatorial governor. In A.D. 37 the emperor Gaius put an end to this arrangement by sending a legatus of his own to take over the command of the legion, thus separating the military from the civil administration, and practically separating Numidia or Africa Nova from Africa Vetus, though the two were still united in name (Tac. Hist. 4.48). Under Septimus Severus (A.D. 1 93 - 211) Numidia was separated from Africa Vetus, and governed by an imperial procurator (procurator per Numidiam); finally, under the new organization of the empire by Diocletian, Numidia became one of the seven provinces of the diocese of Africa, being known as Numidia Cirtensis, and after Constantine as N. Constantina, corresponding closely in extent to the modern French province of Constantine. During all this period it reached a high degree of civilization, and was studded with numerous towns, the importance of which is attested by inscriptions (see vol. viii. of the Corpus inscriptionum), and by the massive remains of public buildings. The invasion of the Vandals in A.D. 428 reduced it to a condition of gradual decay; and the invasion of the Arabs in the 8th century again brought desolation on the land, which was aggravated by continual misgovernment till the conquest of Algeria by the French in 1833.
The chief towns of Numidia under the Romans were: in the north, Cirta, the capital, which still retains the name Constantine given it by Constantine; Rusicada on the coast, serving as its port, on the site now occupied by Philippeville; and east of it Hippo Regius, well known as the see of St Augustine, near the modern Bona. To the south in the interior were Theveste (Tebessa) and Lambaesis (Lambessa) with extensive and striking Roman remains, connected by military roads with Cirta and Hippo respectively. Lambaesis was the seat of the legion III. Augusta, and the most important strategic centre, as commanding the passes of the Mons Aurasius, a mountain block which separated Numidia from the Gaetulian tribes of the desert, and which was gradually occupied in its whole extent by the Romans under the Empire. Including these towns there were altogether twenty which are known to have received at one time or another the title and status of Roman colonies; and in the 5th century the Notitia enumerates no less than 123 sees whose bishops assembled at Carthage in 479.
For bibliography and account of Roman remains, see under Roman Africa.
