The second general sent from Rome in the Jugurthine War, he was replaced by the young G. Marius. Subsequently, he became a strong opponent of the Marian faction.
He spent his youth studying oratory in Athens. He was elected quaestor in 126 BCE, a tribune in 121 BCE, an aedile in 118 BCE, and a praetor in 115 BCE. He also served as governor in Sicily in 114 BCE before being elected consul with Marcus Junius Silanus in 109 BCE.
During the Jugurthine War, Metellus was placed in charge of Numidia. He was a “man of spirit” and “of a consistently unblemished reputation” (BJ 43). The Romans had hope that he would succeed where
Publius Scipio Nasica and
Lucius Calpurnius Bestia had failed because they “were inspired not only by his good qualities as a general, but especially because he possessed a mind superior to riches” (BJ 43). When he arrived in Africa, he had to train the army, which was weak and cowardly (BJ 44). A “great and prudent man,” Metellus did not punish his men, but rather he kept them from doing wrong (BJ 45). He was replaced by
Marius in command of this war through political machinations, and became a stalwart enemy of the populist political faction Marius led.
Upon his return to Rome, however, he was met with great enthusiasm from the opponents of Marius. He was awarded the agnomen, Numidicus, celebrated a triumph, and even had coins minted in honor of his success. He became the leader of the Optimates, the aristocratic faction.
He was elected censor in 102 BCE. During which time, he attempted to expel Lucius Appuleius Saturninus, an ally of Marius, from the Senate. However, he failed, and Saturninus, as tribune of the plebs, worked to pass through an agrarian law, which would award land to the Roman veterans. Though all the Roman senators had to swear loyalty to the new law - lest they be expelled from the senate and face a large fine - Metellus refused. He then went into exile, though he was later allowed to return in 99 BCE.