Lars Tolumnius

Lars Tolumnius ordered the execution of four Roman envoys sent to Veii to demand restitution for an attack on Roman territory. This act violated diplomatic immunity and led to a declaration of war by Rome against Veii, escalating tensions between the two cities.

Lars Tolumnius formed an alliance with the Latin city of Fidenae, which had revolted against Roman control. This alliance strengthened Veii's position and threatened Roman dominance in the region, leading to a prolonged conflict between Rome and the Etruscan-Latin coalition.

Lars Tolumnius led the Veientine army against Rome at the Battle of Fidenae. During the battle, he was killed in single combat by the Roman military tribune Aulus Cornelius Cossus, who dedicated the spolia opima from Tolumnius's armor to Jupiter Feretrius.