But wherever the eye might turn throughout the wide sphere of Roman administration, the same causes and the same effects appeared. If the Sicilian slave-war showed how far the government was from being equal to even its simplest task of keeping in check the proletariate, contemporary events in Africa displayed the skill with which the Romans now governed the client-states. About the very time when the Sicilian slave-war broke out, there was exhibited before the eyes of the astonished world the spectacle of an unimportant client-prince able to carry out a fourteen years' usurpation and insurrection against the mighty republic which had shattered the kingdoms of Macedonia and Asia with one blow of its weighty arm - and that not by means of arms, but through the pitiful character of its rulers.

The kingdom of Numidia stretched from the river Molochath to the great Syrtis[9], bordering on the one side with the Mauretanian kingdom of Tingis (the modern Morocco) and on the other with Cyrene and Egypt, and surrounding on the west, south, and east the narrow district of coast which formed the Roman province of Africa.

In addition to the old possessions of the Numidian chiefs, it embraced by far the greatest portion of the territory which Carthage had possessed in Africa during the times of its prosperity - including several important Old-Phoenician cities, such as Hippo Regius (Bona) and Great Leptis (Lebidah) - altogether the largest and best part of the rich seaboard of northern Africa. Numidia was beyond question, next to Egypt, the most considerable of all the Roman client-states. After the death of Massinissa (605), Scipio had divided the sovereign functions of that prince among his three sons, the kings Micipsa, Gulussa, and Mastanabal, in such a way that the firstborn obtained the residency and the state-chest, the second the charge of war, and the third the administration of justice[10]. Now after the death of his two brothers Massinissa's eldest son, Micipsa[11], reigned alone, a feeble peaceful old man, who was fond of occupying himself more with the study of Greek philosophy than with affairs of state. As his sons were not yet grown up, the reins of government were practically held by an illegitimate nephew of the king, the prince Jugurtha. Jugurtha was no unworthy grandson of Massinissa. He was a handsome man and a skilled and courageous rider and hunter; his countrymen held him in high honour as a clear and sagacious administrator, and he had displayed his military ability as leader of the Numidian contingent before Numantia under the eyes of Scipio. His position in the kingdom, and the influence which he possessed with the Roman government by means of his numerous friends and war-comrades, made it appear to king Micipsa advisable to adopt him (634), and to arrange in his testament that his own two elder sons Adherbal and Hiempsal, and his adopted son Jugurtha along with them, should jointly inherit and govern the kingdom, just as he himself had done with his two brothers. For greater security this arrangement was placed under the guarantee of the Roman government.

Soon afterwards, in 636, king Micipsa died. The testament came into force: but the two sons of Micipsa - the vehement Hiempsal still more than his weak elder brother - soon came into so violent collision with their cousin whom they looked on as an intruder into the legitimate line of succession, that the idea of a joint reign of the three kings had to be abandoned. An attempt was made to carry out a division of the heritage; but the quarrelling kings could not agree as to their quotas of land and treasure, and the protecting power, to which in this case the decisive word by right belonged, gave itself, as usual, no concern about this affair. A rupture took place; Adherbal and Hiempsal were disposed to characterize their father's testament as surreptitious and altogether to dispute Jugurtha's right of joint inheritance, while on the other hand Jugurtha came forward as a pretender to the whole kingdom. While the discussions as to the partition were still going on, Hiempsal was made away with by hired assassins; then a civil war arose between Adherbal and Jugurtha, in which all Numidia took part. With his less numerous but better disciplined and better led troops Jugurtha conquered, and seized the whole territory of the kingdom, subjecting the chiefs who adhered to his cousin to the most cruel persecution. Adherbal escaped to the Roman province and proceeded to Rome to make his complaint there.

Jugurtha had expected this, and had made his arrangements to meet the threatened intervention. In the camp before Numantia he had learned more from Rome than Roman tactics; the Numidian prince, introduced to the circles of the Roman aristocracy, had at the same time been initiated into the intrigues of Roman coteries, and had studied at the fountain-head what might be expected from Roman nobles. Even then, sixteen years before Micipsa's death, he had entered into disloyal negotiations as to the Numidian succession with Roman comrades of rank, and Scipio had been under the necessity of gravely reminding him that it was becoming in foreign princes to be on terms of friendship with the Roman state rather than with individual Roman citizens. The envoys of Jugurtha appeared in Rome, furnished with something more than words: that they had chosen the right means of diplomatic persuasion, was shown by the result. The most zealous champions of Adherbal's just title were with incredible rapidity convinced that Hiempsal had been put to death by his subjects on account of his cruelty, and that the originator of the war as to the succession was not Jugurtha, but Adherbal. Even the leading men in the senate were shocked at the scandal; Marcus Scaurus sought to check it, but in vain. The senate passed over what had taken place in silence, and ordained that the two surviving testamentary heirs should have the kingdom equally divided between them, and that, for the prevention of fresh quarrels, the division should be undertaken by a commission of the senate. This was done: the consular Lucius Opimius, well known through his services in setting aside the revolution, had embraced the opportunity of gathering the reward of his patriotism, and had got himself placed at the head of the commission. The division turned out thoroughly in favour of Jugurtha, and not to the disadvantage of the commissioners; Cirta (Constantine) the capital with its port of Rusicade (Philippeville) was no doubt given to Adherbal, but by that very arrangement the portion which fell to him was the eastern part of the kingdom consisting almost wholly of sandy deserts, while Jugurtha obtained the fertile and populous western half (what was afterwards Mauretania Caesariensis and Sitifensis).

This was bad; but matters soon became worse. In order to be able under the semblance of self-defence to defraud Adherbal of his portion, Jugurtha provoked him to war; but when the weak man, rendered wiser by experience, allowed Jugurtha's horsemen to ravage his territory unhindered and contented himself with lodging complaints at Rome, Jugurtha, impatient of these ceremonies, began the war even without pretext. Adherbal was totally defeated in the region of the modern Philippeville, and threw himself into his capital of Cirta in the immediate vicinity. While the siege was in progress, and Jugurtha's troops were daily skirmishing with the numerous Italians who were settled in Cirta and who took a more vigorous part in the defence of the city than the Africans themselves, the commission despatched by the Roman senate on Adherbal's first complaint made its appearance; composed, of course, of young inexperienced men, such as the government of those times regularly employed in the ordinary missions of the state. The envoys demanded that Jugurtha should allow them as deputed by the protecting power to Adherbal to enter the city, and generally that he should suspend hostilities and accept their mediation. Jugurtha summarily rejected both demands, and the envoys hastily returned home - like boys, as they were - to report to the fathers of the city. The fathers listened to the report, and allowed their countrymen in Cirta just to fight on as long as they pleased. It was not till, in the fifth month of the siege, a messenger of Adherbal stole through the entrenchments of the enemy and a letter of the king full of the most urgent entreaties reached the senate, that the latter roused itself and actually adopted a resolution - not to declare war as the minority demanded but to send a new embassy - an embassy, however, headed by Marcus Scaurus, the great conqueror of the Taurisci and the freedmen, the imposing hero of the aristocracy, whose mere appearance would suffice to bring the refractory king to a different mind. In fact Jugurtha appeared, as he was bidden, at Utica to discuss the matter with Scaurus; endless debates were held; when at length the conference was concluded, not the slightest result had been obtained. The embassy returned to Rome without having declared war, and the king went off again to the siege of Cirta. Adherbal found himself reduced to extremities and despaired of Roman support; the Italians in Cirta moreover, weary of the siege and firmly relying for their own safety on the terror of the Roman name, urged a surrender. So the town capitulated. Jugurtha ordered his adopted brother to be executed amid cruel tortures, and all the adult male population of the town, Africans as well as Italians, to be put to the sword (642).