During the 3rd-2nd centuries BC, the Belli joined the Celtiberian confederacy alongside the Arevaci, Lusones and Titii, with whom they developed close political and military ties – in 153 BC the Numantines even elected the Belli General Caros as leader of the Celtiberian coalition army that ambushed the Consul Quintus Fulvius Nobilior at the battle of Ribarroya, at the Baldano river valley in the beginning of the first Numantine War. Prior to that, they had been forced in 181 BC to accept Roman suzerainty by Tiberius Sempronius Gracchus, but this did not prevent them from resisting further Roman encroachment of their lands as well as fighting off Turboletae raids and the Iberian Lobetani people.