The reason that it is called a Roman Helmet is that during Caesar's conquest of Gaul, he had their leader Vercingetorix surrounded in Alesia when the Gallic reinforcements arrived and surrounded the Romans. Outnumbered and demoralized, Caesar rallied his troops by offering a soldier who had lost his helmet his balls and penis as a replacement. So moved were the troops at Caesar's offer of self-sacrifice that they went on a rampage and defeated the Gauls. The rest is history.
Quarterback: "As leader of this team, I will offer you my Roman Helmet to wear."
Offensive Line (together): "What a leader! Let's go win one for the Gipper!"