Triarii

The Triarii is the third standard line of infantry of the Roman Republican Army. When suffering defeat, the first and second lines, the Hastati and Principes, fell back on the Triarii to attempt to reform the line and allow for a counter attack or withdrawal of the other lines. Because falling back on the Triarii was an act of desperation, to mention, "falling on the Triarii" became a common Roman phrase indicating one to be in a desperate situation.

Triarii, not unlike the Princepes, were divided into ten manipules of 160 men. Each manipule consisted of two centuries consisting of 80 men each, commanded by a Centurion. The Triarii were the veterans of the Roman Army, making them perfectly suited for reinforcing the two front lines of the formation. They were armored much like the rest of the Roman Republican Army, with whatever they could afford.