Spolia opima (or "best spoils/trophies") refers to the armor, arms, and other effects that an ancient Roman general had stripped from the body of an opposing commander slain in single, hand-to-hand combat. Though the Romans recognized and put on display other sorts of trophies--such as standards and the beaks of enemy ships--spolia opima were considered the most honorable to have won and brought great fame to their captor.
Over the course of their entire history, the Romans recognized only three instances of spolia opima having been taken. The first was by Romulus from Acro, king of the Caeninenses; the second by Aulus Cornelius Cossus from Lar Tolumnius, king of the Veientes; the third by Marcus Claudius Marcellus from Viridomarus, king of the Gaesatae (a Celtic tribe of northern Italy). As the first two figures are legendary, or semi-legendary, it may be said that Marcus Claudius Marcellus is the only Roman figure ever to have accomplished this feat.