Regarded as savage and untamable mountaineers, the Cantabri long defied the Roman legions and made a name for themselves for their independent spirit and freedom. Indeed, Cantabri warriors were regarded as being tough and fiercest fighters, suitable for mercenary employment, but prone to banditry. The earliest references to them are found in the texts of ancient historians such as Livy and Polybius, who mention Cantabrian mercenaries in Carthaginian service fighting at the Battle of the Metaurus in 207 BC, and Silius, who talks about a chieftain named Larus recruited by Mago and a Cantabrian contingent in Hannibal's army. Another author, Cornelius Nepos, claims that the Cantabrian tribes first submitted to Rome upon Cato the Elder’s campaigns in Celtiberia in 195 BC. In any case, such was their reputation that when a battered Roman army under consul Gaius Hostilius Mancinus was besieging Numantia in 137 BC, the rumor of the approach of a large combined Cantabri-Vaccaei relief force was enough to cause the rout of 20,000 panic-stricken Roman legionaries, forcing Mancinus to surrender under humiliating peace terms.