In the winter of 102 BCE, one of the legions was sent to the Adige valley, near today’s Trento. Consul Quintus Lutatius Catulus, with this movement, wanted to delay the movements of the incoming Cimbri – Germanic invaders from the north. Unfortunately for the legionaries, the Cimbri encircled their position and prepared to destroy the Roman forces in the valley.
Aware that the only way to survive was to break through the barbarian hordes, Gnaeus Petreius, the legion’s primus pilus, presented the plan to his superior. The commanding tribune, however, was unable to make any decision, probably seeing the situation in which he was just panicked. Petreius, knowing that his and his soldiers’ fates depended on making a quick decision, drew his sword and ended the life of the tribune, and took over the command. His attack was so successful that the Germans did not pursue the Romans.
Upon his return to the consul’s army, Petreius was commended for his actions and received a grass wreath (corona graminea). This decoration was awarded for saving the army from a catastrophe.