The Roman military was successful in invading foreign territories were due in part to the military’s discipline and distribution of punishment for cowardly or offensive behavior.

For instance, there was the punishment of decimatio, which means “decimation” in English. If the soldiers of a unit mutinied, lost a battle or displeased the commander in any way, the commander would divide the army into groups of ten. Then each of the ten soldiers would cast lots, and the person unlucky enough to pick the wrong lot was stoned or clubbed to death by the other nine soldiers. To make matters worse, the remaining nine soldiers were forced to eat reduced rations and were given barley instead of regular grain rations.

Decimatio was not just any old form of physical punishment; it was psychological. Since the soldiers were counted off in random groups of ten, anyone could technically be chosen to die. That means that even if you were the bravest, strongest and most obedient soldier in the army, you could be selected to die anyway. In addition, the officers were counted off separately to be decimated. For instance, centurions would be grouped among other centurions, so that an officer would have to die.

When you think about it, it’s not the brutality of the beating and clubbing that is the worst part of being decimated. (Although, yes, that would be pretty terrible as well.) It’s the fact that the punishment is irrational and random that brings down the army’s morale. If you think about the nine remaining soldiers and how they have to kill one of their peers, what would you feel? Guilt? Relief? Helplessness? To top that off the nine are punished after the fact, with reduced food rations.

Theoretically, decimatio doesn’t necessarily weed out the weakest for selection. It’s just whoever that happens to be the tenth that dies. The worst case scenario of decimatio would be that it would reduce the number of talented individuals needed to lead a successful campaign. The only way decimatio would work is if every soldier believed he had a realistic probability of being the tenth. It’s the randomness that allows each soldier to feel fear of a possible impending punishment.

So, did decimatio really work and scare the Ancient Roman military into shape? It’s hard to say, but we do know that there are written records of when decimatio was used. Supposedly Crassus used it against his Legions when they were defeated by Spartacus. Spartacus was eventually defeated by Crassus’s forces, so maybe decimatio did play a part in Rome’s victories. However, it’s difficult to say that decimatio alone was effective as punishment. Maybe the reduction of rations was the real catalyst behind Rome’s victories.