Rome had been at peace with the tribes of Cisalpine Gaul, the area along the Po valley in northern Italy, since inconclusive skirmishing ceased in 238 BC.

This was deepened in 232 BC when the Romans passed a law allocating large areas of formally Celtic land to poorer citizens.

[5] In 225 BC, the Boii and Insubres paid large sums of money to the Gaesatae, mercenaries from Transalpine Celtic territories led by Aneroëstes and Concolitanus, to fight with them against Rome.

[5] The Romans, alarmed by the Celtic mobilisation, made a treaty giving Carthaginian General Hasdrubal the Fair unimpeded control of Hispania so that they could concentrate on the threat closer to home.

The Roman troops who were stationed on the Etrurian border met them at Clusium, three days march from Rome, where both sides made camp.

That night, the Celts, leaving their cavalry and their camp fires as a decoy, withdrew to the town of Faesulae (modern Fiesole) and built defensive obstacles.

His scouts met the Celts' advance guard head on near Telamon (modern Talamone), in an area called Campo Regio.

[9] Regulus put his troops in fighting order and advanced with his cavalry in an attempt to occupy a hill above the road which would block the Celts' retreat.

They placed the Gaesatae and Insubres at the rear against Papus and the Boii and Taurisci at the front against Regulus, with their flanks protected by a wall of wagons and chariots.

[10] The cavalry battle over the main hill was fierce, and although Papus sent his horsemen to assist Regulus was killed and his head brought to the Celtic leaders.