Why did Polybius retrace Hannibal’s route across the Alps?

Polybius believed that a historian’s essential tasks included the study of documents, political experience, and an acquaintance with relevant geographical features. Consistent with this philosophy, he traveled widely to gain firsthand knowledge of the regions he described.1

His decision to retrace Hannibal’s route across the Alps was part of this commitment to rigorous historical inquiry. By personally traversing the path, Polybius sought to verify the details of the crossing, which he later documented in his Histories. This firsthand exploration allowed him to provide a more accurate account of the terrain, climate, and challenges faced by the Carthaginian army, moving beyond mere hearsay to provide a reliable record for his readers. He likely undertook this journey while traveling with the Roman general Scipio Aemilianus on his way back to Italy.213