Gaius Marius (ca. 157-86 B.C.) was a Roman general and popular politician. His military reforms and great commands led to the growing involvement of the army in politics and the eventual collapse of the republican system.
Born near Arpinum in central Italy, Marius was of country stock. However, his family was well enough situated that Marius could enter a public career in Rome. He saw his first military service in 134-133 B.C. with Scipio Aemilianus (Scipio Africanus Minor) at Numantia, where Marius was decorated for bravery. Ten years later, as military tribune, he may have served under Q. Caecilius Metellus Balearicus against the Balearic pirates. In 122 Marius returned to Rome to be elected to the quaestorship and may have accompanied Q. Fabius Maximus, son of Scipio Aemilianus, to Gaul.
Marius thus earned powerful backing among the Roman nobility. In consequence, under the patronage of the Metelli, he won election to the plebeian tribunate for 119. But in an unexpected show of independence as tribune, he carried a bill limiting the influence of the powerful families at elections and so lost the support of the Metelli. In 118 he ran for the curule and plebeian aedileship and lost both elections. Undaunted, he applied for the praetorship for 116 and won, but he escaped a bribery charge only because of a tie vote by the jury. His praetorship was undistinguished, but he may have placated the nobility and so was made governor of Father Spain. At this point his political career might well have ended.
When Q. Caecilius Metellus Numidicus was sent to Africa in 109 to deal with Jugurtha, he chose Marius as a member of his staff, perhaps to placate equestrian and Italian interests. From the outset Marius intended to use the appointment for his political advancement. Cooperating with equestrians in Africa and popular agitators in Rome, he openly criticized Metellus's conduct of the war. Over Metellus's objections he returned to Rome to run for the consulship for 107. Marius was the first "new man" in 35 years to win the office.
After Marius's election the people voted to transfer the command in Africa to him. When the Senate tried to embarrass him by authorizing the recruitment of additional troops for the unpopular war, Marius took the unprecedented step of enrolling men from the propertyless class, who in the past had been excluded from legionary service. As the people's consul, he intended to win the war with a people's army. Within 2 years Marius beat Jugurtha from the field, but part of the glory of the victory was stolen by his quaestor, L. Cornelius Sulla, who negotiated the surrender of Jugurtha. As a result, bitter enmity developed between Marius and Sulla.
Meanwhile, senatorial leaders had failed to meet a threat to northern Italy from migrating Cimbri and Teutons. In reaction the people turned to Marius, whom they elected in absentia against all constitutional practice to the consulship for 104 and to four successive consulships from 103 to 100. For the northern war, Marius recruited another popular army. He also introduced major reforms in the training and organization of the Roman legions, making the cohort, instead of the smaller maniple, the chief tactical unit. His reorganization continued in effect through the early empire. Again Marius was victorious. He slaughtered the Teutons and Ambrones at Aquae Sextiae in 102 and the Cimbri at Vercellae in 101 to save Italy.
But Marius had won his six consulships not without a price. In 103 the demagogue L. Appuleius Saturninus had attached himself to Marius's cause by passing legislation benefiting Marius's African veterans. In 101 Marius used his veterans to secure the consulship for himself and a second tribunate for Saturninus. As tribune in 100, Saturninus then rammed through an agrarian-colonial bill with the help of the veterans. The bill provided for allotments to veterans in Gaul and called for the establishment of colonies in Sicily and Greece open to Italians as well as veterans and city poor.
When Metellus Numidicus refused to swear the oath attached to the measure, Marius and Saturninus forced him into exile and so got rid of a mutual enemy. But when Saturninus tried for a third tribunate and attempted to install C. Servilius Glaucia in the consulship for 99 by murdering his competitor, Marius abandoned him and cooperated with the Senate in restoring public order.
Marius failed, however, to prevent the lynching of Saturninus and Glaucia and so lost political credit among the city crowd. When Metellus Numidicus was recalled from exile in 98, Marius left for a tour of the East. He returned in 97, but although he still commanded a large following among his veterans and the Italians, he found himself outmaneuvered in Rome by the senatorial leaders whom he had antagonized.
In the Social War, Marius came out of semiretirement to serve as legate to the consul P. Rutilius Lupus in 90. After the death of the consul and another legate, Marius defeated the Marsi and Marrucini and saved the situation in the north. But he refused reappointment in 89 ostensibly for reasons of health but perhaps because he sympathized with the Italians and hoped for the command against Mithridates in the East. To his disappointment the Senate awarded the Eastern command to Sulla, who was elected consul for 88.
But to get Marian support for his proposal to distribute the new Italian citizens in all the tribes, the tribune P. Sulpicius Rufus introduced a bill to transfer the command to Marius and pushed his measures through with the help of Marius's veterans. When Sulla marched on Rome to reclaim the command, he had Marius and Sulpicius declared public enemies. Marius fled to Africa after barely escaping execution at Minturnae.
In Africa, Marius watched for an opportunity to return to Rome. It came when Gnaeus Octavius deposed his colleague L. Cornelius Cinna for again trying to support Italian claims for full franchise. Marius joined Cinna in his march on the city, collecting an army in Etruria and taking charge of Cinna's military operations. When Octavius surrendered and Cinna was again recognized as consul, Marius grimly refused to enter the city until the sentence of exile had been formally repealed by the people. For the murders and executions which followed his entry into the city, Marius was only partly responsible. Cinna deliberately planned some, and others were committed by the victorious troops, who got out of hand, or by lesser men seeking private revenge. There is no evidence that Marius was mentally unbalanced when he returned to Italy.
To reward Marius for his services, Cinna reassigned to him the Eastern command and chose him as his colleague in the consulship for 86. But, 70 years old and worn out by the rigors of his exile and return, Marius took sick shortly after entering that office for the seventh time. He died of pneumonia on Jan. 13, 86.
The chief ancient sources for Marius are Plutarch, Life of Marius; Sallust, Jugurthine War; and Appian, Bellum Civile. For a sympathetic view of Marius and a full discussion of the major problems see T. F. Carney, A Biography of C. Marius (1961; 2d ed. 1970). The Cambridge Ancient History, vol. 9 (1932), and H. H. Scullard, From the Gracchi to Nero (1959; 2d ed. 1963), give valuable accounts of Marius's career. See also Phillip A. Kildahl, Caius Marius (1968).