The Triumph of Marius the Great

Marius made the army a career choice, not just an obligation for men with better things to do. Marius also promoted from within, taking the best of his foot soldiers and making them officers when they displayed courage and initiative. The nobility derisively referred to the soldiers as Marius's mules but by a factor of 10, the marching and drilling left Marius's legions in the best shape of any Roman army in history.