A cuirass is a piece of armor which encases a soldier's upper body, without having the form of a shirt. It consists of two plates of bronze, steel, or hardened leather. The front plate protects the thorax, abdomen, and the rear plate protects the back from shoulder to lumbar spine. The plates are held together by straps or hinges at the shoulders, and along each side under the arms.

Some cuirasses were finely tailored to the contours of an individual's torso, while others were more general in nature, and would fit any soldier of a particular size and physique.

In Ancient Rome, the soldiers who held the highest of ranks--generals and legates--wore cuirasses tooled in high relief and silver-plated (or, rarely, gold-plated).

Many generals and their most senior legates wore a thin red sash around the cuirass about halfway between the nipples and waist. These sashes were ritually looped and knotted, and their use is presumed to have been an indicator of the wearer's imperium.