# Why was a Centurion in charge of just 80 men? **URL:** \ **Category:** Factual Questions\ **Created:** [July 29, 2003, 4:28pm UTC](https://boards.straightdope.com/t/why-was-a-centurion-in-charge-of-just-80-men/191686 "2003-07-29T16:28:28Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![G.Cornelius](https://avatars.discourse-cdn.com/v4/letter/g/b782af/32.png) [@G.Cornelius](https://boards.straightdope.com/u/G.Cornelius)\ **Post date:** [July 29, 2003, 4:28pm UTC](https://boards.straightdope.com/t/why-was-a-centurion-in-charge-of-just-80-men/191686/1 "2003-07-29T16:28:28Z")
In the Imperial Roman army, a century in fact consisted of just 80 legionaries. Why not 100? ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [July 29, 2003, 4:33pm UTC](https://boards.straightdope.com/t/why-was-a-centurion-in-charge-of-just-80-men/191686/2 "2003-07-29T16:33:41Z")
Originally, it was 100, but there were re-organizations, and the new size of a “century” came to be 80, but the name stuck. I can bet some 1st Century Stand-up made that joke, along with “who was that Patrician I saw you with last night?- That was no Patrician, that was my wife”. 😃 ---
**Author:** ![MC\_Master\_of\_Ceremonies](https://avatars.discourse-cdn.com/v4/letter/m/bb73d2/32.png) [@MC\_Master\_of\_Ceremonies](https://boards.straightdope.com/u/MC_Master_of_Ceremonies)\ **Post date:** [July 29, 2003, 4:37pm UTC](https://boards.straightdope.com/t/why-was-a-centurion-in-charge-of-just-80-men/191686/3 "2003-07-29T16:37:08Z")
> [@](#): > > The decuria is the smallest unit used by the Imperial military, composed of nine legionnaires and their serjeant. An archaic title for this unit is the contubernium, or tentmates. Each decuria is permitted one mule to carry equipment and one servant to care for the mule. > > Centuries > > ``` > The century is composed of ten to twelve decuriae, commanded by a centurion, who generally fights either on the front line or the third. Each century also has an Optio (also called a Junior Centurion or Lieutenant), who is second-in-command and fights from the rear rank, a Pilus Primus, who carries the standard identifying the unit in the third rank, and a herald, who carries a signalling trumpet (the latter two officers are the only of these that are part of a decuria). Each centurion is permitted one mule, one servant to care for the mule, one servant to care for his personal affects, and an engineer. The Optio is permitted one mule and one servant to care for the mule. Thus, the century is composed of 116 to 138 men (90 to 108 legionaires, 10 to 12 serjeants, 1 centurion, 1 optio, 1 engineer and 13 to 15 > > ``` [http://members.aol.com/noctifer/private/Feyworld/DJ/GreatEmpire/Chap3/org.html#Decuria](http://members.aol.com/noctifer/private/Feyworld/DJ/GreatEmpire/Chap3/org.html#Decuria) No centuries usually had more than 100 men, though it could of possibly had less than 100 legionaires. ---
**Author:** ![Bryan\_Ekers](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bryan_ekers/32/183_2.png) [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)\ **Post date:** [July 29, 2003, 6:55pm UTC](https://boards.straightdope.com/t/why-was-a-centurion-in-charge-of-just-80-men/191686/4 "2003-07-29T18:55:26Z")
Budget cuts. ---
**Author:** ![MonkeyMensch](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@MonkeyMensch](https://boards.straightdope.com/u/MonkeyMensch)\ **Post date:** [July 29, 2003, 9:52pm UTC](https://boards.straightdope.com/t/why-was-a-centurion-in-charge-of-just-80-men/191686/5 "2003-07-29T21:52:23Z")
Actually, the century was based on Base 10. Hence it was easier for finger math for the centurion. It’s the same reason Irish math is Base 7… Damn farmers ---
**Author:** ![Shortie](https://avatars.discourse-cdn.com/v4/letter/s/ecd19e/32.png) [@Shortie](https://boards.straightdope.com/u/Shortie)\ **Post date:** [July 29, 2003, 10:22pm UTC](https://boards.straightdope.com/t/why-was-a-centurion-in-charge-of-just-80-men/191686/6 "2003-07-29T22:22:10Z")
> [@](#): > > \*Originally posted by MC Master of Ceremonies \* > \*\*[http://members.aol.com/noctifer/private/Feyworld/DJ/GreatEmpire/Chap3/org.html#Decuria](http://members.aol.com/noctifer/private/Feyworld/DJ/GreatEmpire/Chap3/org.html#Decuria) > > No centuries usually had more than 100 men, though it could of possibly had less than 100 legionaires. \*\* It’s a nice site, but while it’s clearly based on Rome, I’m pretty sure it’s describing the fictional land of Zeth (check the link at the bottom and the history page from there). How about [here](http://www.roman-empire.net/army/army.html) for a site which is about our Rome: > [@](#): > > The army as operated from the time of Augustus can generally be referred to as the ‘classic’ legion, the armed body of men which most imagine in their minds upon hearing the word ‘legion’. And it is this state of the legion which is largely recreated in illustrations or Hollywood movies. > … > > 1 Contubernium = 8 Men > 10 Contubernia =1 Century 80 Men > 2 Centuries = 1 Maniple 160 Men > 6 Centuries = 1 Cohort 480 Men > 10 Cohorts + 120 Horsemen = 1 Legion 5240 Men \* > > \*1 Legion = 9 normal cohorts (9 x 480 Men) + 1 “First Cohort” of 5 centuries (but each century at the strength of a maniple, so 5 x 160 Men) + 120 Horsemen = 5240 Men > > Together with non-combatants attached to the army, a legion would count around 6000 men. > The 120 horsemen attached to each legion were used as scouts and dispatch riders. They were ranked with staff and other non-combatants and allocated to specific centuries, rather than belonging to a squadron of their own. It doesn’t give a reason for the number being 80 but that leads on from the tent-party being 8, and presumably that was 10 before one of the many re-organisations of the army. ---
**Author:** ![Declan](https://avatars.discourse-cdn.com/v4/letter/d/ecae2f/32.png) [@Declan](https://boards.straightdope.com/u/Declan)\ **Post date:** [July 30, 2003, 12:53am UTC](https://boards.straightdope.com/t/why-was-a-centurion-in-charge-of-just-80-men/191686/7 "2003-07-30T00:53:14Z")
It got decimated ,lol Declan ---
**Author:** ![RickJay](https://avatars.discourse-cdn.com/v4/letter/r/bb73d2/32.png) [@RickJay](https://boards.straightdope.com/u/RickJay)\ **Post date:** [July 30, 2003, 12:59am UTC](https://boards.straightdope.com/t/why-was-a-centurion-in-charge-of-just-80-men/191686/8 "2003-07-30T00:59:47Z")
Redefinition of the size of army formations is a pretty common occurrence throughout history. ---
**Author:** ![AK84](https://avatars.discourse-cdn.com/v4/letter/a/85e7bf/32.png) [@AK84](https://boards.straightdope.com/u/AK84)\ **Post date:** [December 23, 2012, 9:03am UTC](https://boards.straightdope.com/t/why-was-a-centurion-in-charge-of-just-80-men/191686/9 "2012-12-23T09:03:22Z")
I believe in varied actually. It was not uncommon to a century to be on separate duty at an isolated post with supporting cavalry, archers and sappers attached. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [December 23, 2012, 1:10pm UTC](https://boards.straightdope.com/t/why-was-a-centurion-in-charge-of-just-80-men/191686/10 "2012-12-23T13:10:05Z")
Reminds me of this amusing quotation attributed to Heraclitus I ran across: > [@](#): > > Out of every one hundred men, ten shouldn’t even be there, eighty are just targets, nine are the real fighters, and we are lucky to have them, for they make the battle. Ah, but the one, one is a warrior, and he will bring the others back. ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [December 23, 2012, 1:28pm UTC](https://boards.straightdope.com/t/why-was-a-centurion-in-charge-of-just-80-men/191686/11 "2012-12-23T13:28:34Z")
> [@AK84](#): > > I believe in varied actually. It was not uncommon to a century to be on separate duty at an isolated post with supporting cavalry, archers and sappers attached. That’s always the case, even today. Go anywhere in the world where an army is deployed, and you’ll find an infantry company minus one platoon assigned elsewhere, reinforced by a two tanks and an engineering squad… ---
**Author:** ![moriah](https://avatars.discourse-cdn.com/v4/letter/m/b2d939/32.png) [@moriah](https://boards.straightdope.com/u/moriah)\ **Post date:** [December 23, 2012, 4:06pm UTC](https://boards.straightdope.com/t/why-was-a-centurion-in-charge-of-just-80-men/191686/12 "2012-12-23T16:06:55Z")
> [@Bryan\_Ekers](#): > > Budget cuts. Sequestration. Rome was heading for a fiscal [del]cliff[/del] decline and fall. ---
**Author:** ![kaylasdad99](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kaylasdad99/32/3398_2.png) [@kaylasdad99](https://boards.straightdope.com/u/kaylasdad99)\ **Post date:** [December 23, 2012, 4:16pm UTC](https://boards.straightdope.com/t/why-was-a-centurion-in-charge-of-just-80-men/191686/13 "2012-12-23T16:16:41Z")
One of the Roman emperors was missing a finger, so he decreed that the empire would henceforth operate on a base 9 system (9[sup]2[/sup] = 81, which is 80 soldiers + 1 centurion). What? IT COULD HAPPEN! ---
**Author:** ![Alan\_Smithee](https://avatars.discourse-cdn.com/v4/letter/a/2acd7d/32.png) [@Alan\_Smithee](https://boards.straightdope.com/u/Alan_Smithee)\ **Post date:** [December 23, 2012, 8:55pm UTC](https://boards.straightdope.com/t/why-was-a-centurion-in-charge-of-just-80-men/191686/14 "2012-12-23T20:55:36Z")
Everyone is assuming the name was originally accurate and the number of men was decreased. Maybe it was always 80 men, and the officers “rounded up” in calling themselves centurions because it sounded better. If you’re picking up chicks at the bar and your buddy starts bragging about how he commands “almost a hundred” men, are you going to be a stickler for accuracy and say you command eighty, or are you going to start telling folks you command “about a hundred”? ---
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [December 23, 2012, 10:02pm UTC](https://boards.straightdope.com/t/why-was-a-centurion-in-charge-of-just-80-men/191686/15 "2012-12-23T22:02:01Z")
At a fundamental level, it’s around the limit one man can command using only voice. (Yes, a general can shout, “Forward!” and have thousands of troops move out, but he can only command that many through intermediaries, and 75-100 makes a natural break in the number one man can keep track of and effectively direct.) ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [December 23, 2012, 10:35pm UTC](https://boards.straightdope.com/t/why-was-a-centurion-in-charge-of-just-80-men/191686/16 "2012-12-23T22:35:35Z")
That’s why even today, infantry companies are about 100 men strong. ---
**Author:** ![AK84](https://avatars.discourse-cdn.com/v4/letter/a/85e7bf/32.png) [@AK84](https://boards.straightdope.com/u/AK84)\ **Post date:** [December 24, 2012, 5:41am UTC](https://boards.straightdope.com/t/why-was-a-centurion-in-charge-of-just-80-men/191686/17 "2012-12-24T05:41:53Z")
Also, IIRC Centurion was a rank with many grades with differing responsibilities at each (like General today). You started with a Centurion in command of a Century, 80 men, went up to Centurion in command of about 500 men ( a cohort) unto the First spear centurion, who commanded nearly thousand men, the first cohort. In addition, Centurions also commanded attached archers and cavalry as well as the logistics troops of a legion, who would vary in number. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [December 24, 2012, 6:24am UTC](https://boards.straightdope.com/t/why-was-a-centurion-in-charge-of-just-80-men/191686/18 "2012-12-24T06:24:29Z")
> [@NitroPress](#): > > At a fundamental level, it’s around the limit one man can command using only voice. (Yes, a general can shout, “Forward!” and have thousands of troops move out, but he can only command that many through intermediaries, and 75-100 makes a natural break in the number one man can keep track of and effectively direct.) > [@Alessan](#): > > That’s why even today, infantry companies are about 100 men strong. Fascinating. ETA: “and 75-100 makes a natural break in the number one man can keep track of and effectively direct.” Debateable. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [December 24, 2012, 9:19am UTC](https://boards.straightdope.com/t/why-was-a-centurion-in-charge-of-just-80-men/191686/19 "2012-12-24T09:19:42Z")
Maybe it’s for the same reason centipedes don’t have 100 feet and millipedes don’t have 1000. ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [December 24, 2012, 9:40am UTC](https://boards.straightdope.com/t/why-was-a-centurion-in-charge-of-just-80-men/191686/20 "2012-12-24T09:40:03Z")
> [@dtilque](#): > > Maybe it’s for the same reason centipedes don’t have 100 feet and millipedes don’t have 1000. Well, no. It’s not as if the people who gave the centipede its name also designed it. [Next page](https://boards.straightdope.com/t/why-was-a-centurion-in-charge-of-just-80-men/191686.md?page=2)