The Cantabrian circle (Latin: circulus cantabricus) was a military tactic born in the warfare in the ancient Iberian peninsula. It was employed by ancient and to a lesser extent medieval light cavalry armed with javelins or bows. As Flavius Arrianus and Hadrian relate, this was the most habitual form to appear in combat of the Cantabri tribes, and Rome adopted it after the Cantabrian Wars.