What is the name of the metal boss found at the center of a shield?

The correct answer, Umbo, refers to the raised central part of a shield, typically made of metal. This feature not only serves a decorative purpose but also provides structural integrity, helping to deflect blows during combat. The umbo often projects outward, making it easier for a warrior to parry attacks effectively.

In ancient Roman martial culture, the use of the umbo was crucial as it allowed soldiers to defend themselves more efficiently while maintaining the functionality of their shields. It was a standard component of design in many types of shields throughout history, especially in the classical and medieval periods.

The other choices have distinct meanings and uses. Umbra refers to shade or shadow, often used in the context of eclipses. Orbis means "circle" or "disk" and can refer to various circular objects or concepts in ancient texts. Galea, meanwhile, is the term for a helmet, specifically that of a soldier, which does not pertain to shield design. Understanding these definitions highlights the importance of the umbo in the context of ancient warfare and shows how specific terminology reflects different elements of military equipment.