Gaius Marius was a Roman general born in about 155 B.C., in Cereatae, in the Volscian territory.
He won his first military repute at Numantia in 134, beginning his rapid rise from the ranks; was made tribune of the people in 119; increased his political power by marrying Julius Caesar's aunt; became praetor in 115; went to Spain in the next year, suppressing brigandage there; and in 109 accompanied Metallus to Africa. Two years later he was chosen consul, displaced his superior officer and made a brilliant campaign. His success was so great that he was elected consul four times in succession (104-101 B.C.), a proceeding counter to law and entirely unparalleled, so as to meet the invasion of Italy by the Cimbri and Teutons.
He defeated the latter tribe at Aix in 102, and the Cimbri near Vercellae in 101. In 100 he was again elected consul. He made the fatal mistake of plunging into party politics, allied himself with the most disreputable leaders of the popular party, and, in his envy of the rising fame of the patrician Sulla, attempted to remove him from his command in the Jugurthine War.
Civil war broke out in 88. Sulla was victorious. Marius fled to Africa, whence he returned to Italy on the successful rising in Rome under Lucius Cornelius Cinna. The first great proscription followed and many of Marius' opponents were killed. Marius was elected consul for the seventh time in 86 B.C.
Marius died in Rome on January 13, 86 B.C.