Marius’ life and career was particularly relevant to ancient Rome’s history and the transformation from Republic to Principate (Empire). He:
Implemented radical military reforms in 107BC extending the professional army model:
Enabling relatively poor plebeians to enter the army. His conscripts came to be known as “Marius’ Mules” because of the equipment and baggage they each carried great distances.
Creating a regular standing army.
Victories against two Germanic (possibly Celtic) tribes called the Cimbri and Teutones which around 106BC heavily defeated the Romans and in 102BC threatened to enter northern Italy.
Leading part in the civil wars, optimates versus populares (nobles versus plebeians) , against his ex lieutenant, general Sulla which ended in great bloodshed and proscriptions.
The young Julius Caesar barely survived and soon had himself noticed when he took public office by restoring Marius’ war trophies to the temples.
Please refer to marius and the republic and Sulla deposes Marius for further insight of this great Roman leader.