Decimation

Decimation was a form of punishment used by various commanders in the Roman Army, most notably Marcus Licinius Crassus, during the Third Servile War. It involved taking a varied number of men and lining them up. Every tenth man was taken and they were beaten or stoned to death by nine other soldiers of the decimated men.

Caligula attempted to decimate the men while he was trying to invade Britain, but decided against it after advice from his uncle, Claudius.