One of my regular correspondents wrote to me today about in part the misuse of the word Decimation.

Decimation (Latin: decimatio; decem = “ten“) was a form of military discipline used by senior commanders in the Roman Army to punish units or large groups guilty of capital offences such as mutiny or desertion. The word decimation is derived from Latin meaning “removal of a tenth”. The procedure was a pragmatic attempt to balance the need to punish serious offences with the practicalities of dealing with a large group of offenders.

Procedure
A cohort selected for punishment by decimation was divided into groups of ten; each group drew lots (Sortition), and the soldier on whom the lot fell was executed by his nine comrades, often by stoning or clubbing. The remaining soldiers were often given rations of barley instead of wheat for a few days, and required to camp outside the marching camp.

Because the punishment fell by lot, all soldiers in the group were eligible for execution, regardless of the individual degree of fault, or rank and distinction, unless rigged to eliminate the mutiny ringleaders. The leadership was usually executed independently of the one in ten deaths of the rank and file.

Sources
The earliest documented decimation occurred in 471 BC during the Roman Republic‘s early wars against the Volsci and is recorded by Livy. In an incident where his army had been scattered, consul Appius Claudius Sabinus Inregillensis had the culprits punished for desertion: Centurions, standard-bearers and soldiers who had cast away their weapons were individually scourged and beheaded, while of the remainder, one in ten were chosen by lot and executed.

The practice was revived by Crassus in 71 BC during the Third Servile War against Spartacus, and some historical sources attribute part of Crassus’ success to it. The amount of men killed through decimation is not known, but it varies between 1,000 (used on 10,000 men), or a cohort of around 480-500 men, meaning only 48-50 were killed.

Julius Caesar threatened to decimate the 9th Legion during the war against Pompey, but never did.

Polybius gives one of the first descriptions of the practice in the early 3rd century BC:If ever these same things happen to occur among a large group of men… the officers reject the idea of bludgeoning or slaughtering all the men involved [as is the case with a small group or an individual]. Instead they find a solution for the situation which chooses by a lottery system sometimes five, sometimes eight, sometimes twenty of these men, always calculating the number in this group with reference to the whole unit of offenders so that this group forms one-tenth of all those guilty of cowardice. And these men who are chosen by lot are bludgeoned mercilessly in the manner described above.

Here is what he wrote. What do you think?

Dear Robin, On David Dimbleby´s boring ´Question Time´ from Portsmouth last night (and what an exceptional bore Ed Davey is) we heard more than once of the decimation of the Royal Navy. Were it decimation (one in ten ships lost) there would be cause for rejoicing.