Jugurtha was the nephew and adopted son of Micipsa, king of Numidia, whom he succeeded to the throne; he had done so by overcoming his rivals through assassination, war, and bribery.

Numidia was a kingdom located in North Africa (roughly corresponding to northern modern day Algeria) adjacent to what had been Rome's arch enemy, Carthage.

Hiempsal, who, though the younger, was the braver of the brothers, was assassinated by Jugurtha's agents, and Adherbal, unable to defend himself, was defeated and forced to flee to Rome, where he appealed for arbitration to the Roman Senate.

The Roman Senate organized a commission, led by the ex-Consul Lucius Opimius, to fairly divide Numidia between the remaining two contestants, starting in 116 BC.

However, Jugurtha bribed the Roman officials in the commission into allotting him the better, more fertile and populous western half of Numidia, while Adherbal received the east.

King Jugurtha, pretending to be open to discussion, protracted negotiations with Scaurus and Adherbal long enough for Cirta to run out of provisions and hope of relief.

Jugurtha assassinated him, and the Senate, though initially inclined to accept bribery again to allow him to escape retribution,[13] was ultimately compelled by his insolence and by the fury of the mob to expel him from the city and revoke the recent peace.

[15] The beaten Postumius signed a treaty permanently naming Jugurtha the king of all of Numidia and returning to the peace concluded with Bestia and Scaurus.

[16] After Postumius' defeat, the Senate finally shook itself from its lethargy, appointing as commander in Africa the plebeian Quintus Metellus, who had a reputation for integrity and courage.

Both Gaius Marius (a plebeian from Arpinum) and the noted disciplinarian and military theorist Publius Rutilius Rufus documented Metellus' commitment to merit and expertise in his officer corps.

The crafty Jugurtha, guessing Metellus' intentions, broke off the talks and withdrew south beyond the Numidian mountains, taking up position on the plains behind them.

Rufus overpowered the southern detachment by a forward charge which scattered the war elephants and infantry of the enemy, while Metellus and Marius, rallying a group of legionaries, occupied the single hill on the plain, which commanded the situation.

[20] A fresh round of negotiations came to nothing, with Metellus rejecting Jugurtha's heavy concessions and demanding that the king surrender himself into Roman custody.

[21] To resist the Romans more effectually, Jugurtha dismissed most of his low-quality recruits, keeping only the most active troops of infantry and light cavalry, in order to maintain the war by guerrilla tactics.

He tried to provoke Jugurtha into a pitched battle by besieging the Numidian city of Zama, but the king refused to let himself be goaded and kept up his irregular warfare.

Metellus looked unfavourably on Marius' known ambitions in Roman politics and refused for days to allow him to sail to Rome and stand for the consulship.

[30][dubious – discuss] When Gaius Marius arrived in Numidia as consul in 107 BC, he immediately ceased negotiation and resumed the war.

Marius' strategy was similar to Metellus' and yielded no better results; he continued the occupation of Numidian towns and he fortified several strategic positions.

[32] By marching so far to the west Marius had brought the Roman army very near to the dominions of king Bocchus, finally provoking the Mauretanian into direct war, joining the side of Jugurtha.

[33] Marius's army thus finished the year's campaigns in safety at Cirta, but it was by now evident that Rome could not defeat Jugurtha's guerrilla tactics through war.

[34] In the aftermath, Bocchus annexed the western part of Jugurtha's kingdom, and was made a friend of the Roman people (a term used to describe a foreign king in good standing with Rome).

Jugurtha was thrown into an underground prison (the Tullianum) in Rome, and was ultimately executed after gracing Marius's Roman triumph in 104 BC.

[36][dubious – discuss] The fact that a man such as Jugurtha could have his treachery, conquests, and defiances ignored simply by buying Roman military and civil officials reflected Rome's moral and ethical decline.