Battle of Pharsalus
Flanking on land in the pre-modern era was usually achieved with cavalry (and rarely, chariots) due to their speed and maneuverability, while heavily armored infantry was commonly used to fix the enemy, as in the Battle of Pharsalus. Armored vehicles such as tanks replaced cavalry as the main force of flanking maneuvers in the 20th century, as seen in the Battle of France in World War II.