The Roman legion was a highly disciplined, well-trained, and heavily armed body of infantry, which, in the first century AD, comprised between five and six thousand men (the exact number is not stated in the classical literature), all of whom were Roman citizens. The centurion was a professional soldier who had risen in the ranks and provided discipline and leadership for the army. He was identified by the transverse crest on his helmet, his mail or scale armor, and shin guards. The centurion also wore his sword (gladius) on the left and his dagger (pugio) on the right, just the reverse of the legionary soldier, and carried a vine stick (vitis) as a badge of his rank and to discipline the troops. He might also wear medals of valor (phalerae). Promotion to the centurionate was by the provincial governor and the pay twenty times that of a legionary.

An arena is a large enclosed platform, often circular or oval-shaped, designed to showcase theatre, musical performances, or sporting events. It is composed of a large open space surrounded on most or all sides by tiered seating for spectators, and may be covered by a roof. The key feature of an arena is that the event space is the lowest point, allowing maximum visibility. Arenas are usually designed to accommodate a multitude of spectators.