Marcellus military exploits were largely unmatched by any other aristocrat of Roman Middle Republic. As a young soldier in the First Punic War, he won a reputation for his skill in single combat. In his first consulship, he earned a triumph for defeating a Gallic tribe, no small feat in and of itself, and also slew the Gallic chieftain Britomartus in single combat. Consequently, he earned the spolia opima, an honor, according to Roman antiquarians, which had only been earned twice before, once by Romulus himself. He went on to defeat the hitherto-invincible Hannibal in a small battle around the central Italian city of Nola, and subsequently led an army to subdue and plunder the powerful city of Syracuse in an epic 2 year siege (despite the ingenious defensive measures of the inventor Archimedes). Yet, despite his undeniable success as a warrior and commander, Marcellus met with considerable political opposition at Rome.