In 113 BC, the Cimbri and Teutoni invaded the lands of one of Rome's allies, the Taurisci, where they defeated a Roman army sent to defend the Taurisci. Continuing their migration southward and westward, some of the Cimbri passed through Gaul and into Spain, while others moved towards Italy. On their way, they picked up other allies among the resident Germanic and Celtic peoples. They came into frequent conflict with the Romans, who usually came out the losers. One of the greatest defeats the Romans suffered at the hands of the Cimbri and their allies was in 103 BC, when the proconsul Caepio and the consul Gn. Mallius Maximus lost as many as 20,000 men.
By 102 BC, those Cimbri who had been in Spain had returned to join with their former comrades in a movement towards Italy. The consul Marius led the campaigns against the Cimbri, whom his troops eventually destroyed at Vercellae.