The Battle of Clastidium was fought in 222 BC between a Roman army led by the consul Marcus Claudius Marcellus and a Celtic force of the transalpine Gaesatae, called by the cisalpine Insubres. The Gaesatae were led by Viridomarus (Florus) or Britomartus (Plutarch), as the name varies in translation. The Romans won the battle, and in the process, Marcellus earned the spolia opima, one of the highest honors in ancient Rome, by killing the king in single combat. It was also notable as one of the few battles won by the Roman cavalry without any aid by the legions.