Gaius Marius (157–86 b.c.e.), born in Arpinus into a plebeian family, began his public career during the war against Jugurtha, where he won the support of the popular party because of his military victories, and was elected consul in 107 b.c.e.
From 113 b.c.e. the Romans had been facing various defeats against such Germanic tribes as the Cimbri and Teutons that were heading into Italy. Marius commanded the army, and the Senate allowed his consulship to be renewed for three consecutive years.
In 100 b.c.e. Marius was elected to the consulship for the sixth time, and by then he had forged a political alliance with Saturninus, the tribune of the plebs, who promoted a law in order to continue the Gracchan reforms on land distribution.
The proposal included an extension of the privilege to the members of the populus who had served the army: Spoils of war and landparcels would constitute an appropriate payment for their service.
However, the Senate immediately rejected the law, and Marius could not stand by the proposal; he had to suppress the arising rebellions instead. Suspected by all—since the aristocracy took him as an unfaithful partner and the plebs regarded him as a potential traitor—Marius left for the East.
He was called back to Rome in 91 b.c.e. when Italic allies had started to rise up because of the profound differences existing between Rome and the conquered cities. The Italic war lasted for three years, and Marius managed to appease the rebellion. Marius had come back to the urbs and seemed to have recovered part of his prestige.
While Rome was focused on the reorganization of its territory, the East was preparing to separate from the urbs, and by 89 b.c.e. most Eastern cities were supporting Mithridates VI, king of Pontus.
A new dispute, related to the appointment of the military commander who would have to fight the new threat, arose in Rome. The task was finally entrusted to Lucius Cornelius Sulla, a consul chosen in 88 b.c.e., who belonged to the small aristocracy and had served as a lieutenant to Marius for years.
Having taken Caecilia Metella, daughter of the pontifex maximus and princeps senatus, as his fourth wife, the aristocracy considered him to be its natural representative. Nevertheless, the tribune Suplicius Rufus rejected this idea and, supported by the popular party, wanted Marius to be named general instead.
Sulla then escaped to Campania and fiercely moved the legions against Rome. By the time they got there Marius had already escaped to Africa as a fugitive; many opposing leaders were brutally killed. The civil war between optimates and populares raged.
Sulla decided to travel to Greece and deal with the Eastern conflict. Marius came back and joined Cinna, who was promoting subversion in the provinciae. After shaping an army they headed toward Rome and implemented a violent consulship; many members of the senatorial and equestrian orders were killed.
In 87 b.c.e. Marius died, and Valerius Flaccus was appointed as his successor. Sulla, immersed in an unfavorable situation, let his army plunder the cities of Epidaurus, Delphi, and Olympus. After the reduction of Athens, he reorganized his men and defeated Mithridates in Chaeronea and Orchomenus.
He pacified the rival Roman army that had killed Flaccus in rebellion and forced Mithridates to sign a peace treaty. When he arrived back in Rome, where Cinna was ruling, civil war began again. Sulla finally disembarked in Brindisium. Cinna tried to stop him but was killed in combat.
Rioting started in Rome, where power was still in the hands of the populares, led now by the younger Marius, son of Gaius Marius. Marius declared Sulla a public enemy and tried more than once to face him in battle but was also overcome by Sulla’s troops. In 81 b.c.e. Sulla’s triumph was absolute.
As supreme leader in Rome, Sulla put into practice several despotic acts. He promoted the systematic murder of his opponents and elaborated a list (proscriptio) of the names of those citizens whom he considered undesirable and wished to have eliminated.
An aristocratic restoration was achieved, and the Assembly was weakened with the intention of increasing the Senate’s power. During his rule Sulla granted himself the title of "dictator" and exercised an autocratic power. Once he thought his reforms were enacted, in 78 b.c.e., he resigned the dictatorship and left Rome. He died soon afterward in southern Italy.