On his return to Italy, he advanced at once to meet Hannibal. In a sharp cavalry engagement near the Ticinus, a tributary of the Po river, he was defeated and severely wounded. In December of the same year, he again witnessed the complete defeat of the Roman army at the Trebia, when his fellow consul Tiberius Sempronius Longus allegedly insisted on fighting against his advice. [The earliest historical source was by the Greek historian Polybius, who became an intimate of Scipio's grandson and was seemingly biased in favour of the Scipio family. The other major account was written in the following century by the Roman historian Livy, who also expressed bias in favour of certain aristocratic families.]