\"Decurion\" vs. \"decanus\"

[TIM]

I understand that the term "decurion" originally was applied to either an infantry or a cavalry leader of 10, but that in time, it came to mean a cavalry squadron commander (30 men & their mounts), and that an infantry "patrol leader" of 8 (one contubernium--no longer 10) came to be called a "decanus." If this is correct, please confirm it. If not, please correct it. If correct, when did the term "decanus" come into usage?

[Gnaevs Domitivs Corbvlo]

I found a source saying 1st century AD.

[Kegluneq]

Note the previous discussion on the topic here (and possibly elsewhere, could only find that). The primary historical source for this rank is Vegetius (2.8.10), who also thought a contubernium had ten men. There's further discussion of the role here - note the role of the biarchus.

Although it would make sense from a modern perspective to have a level of command at the 'fire team' level (ie a sergeant), I don't think there's anything to suggest there was ever a formal rank for this in the Roman military, and neither Domaszewski or Breeze seem to include it in their studies of sub-centurial ranks. The smallest tactical unit used in battle was the century (or the turma).

If the decanus existed in earlier armies, his duties would have simply been to organise the erection of the tent, supervise collection of supplies etc (ie the roles of the biarchus). It may have been self-applied by ambitious individuals, perhaps?

[Sean Manning]

I understand that the term "decurion" originally was applied to either an infantry or a cavalry leader of 10, but that in time, it came to mean a cavalry squadron commander (30 men & their mounts), and that an infantry "patrol leader" of 8 (one contubernium--no longer 10) came to be called a "decanus." If this is correct, please confirm it. If not, please correct it. If correct, when did the term "decanus" come into usage?

Although its derived from the Latin for ten (decem) I don't think that proves that the Roman army ever had a unit of ten men. Just as likely, decurio and centurio could have come from units of "about ten" and "about a hundred" men. We see this in, for example, the Persian garrison on Elephantine where units whose Aramaic names mean decuria and centuria have many less men. There is no evidence that this reflects casualties or failure to recruit enough men (in peacetime?)

[Mark Hygate]

I understand that the term "decurion" originally was applied to either an infantry or a cavalry leader of 10, but that in time, it came to mean a cavalry squadron commander (30 men & their mounts), and that an infantry "patrol leader" of 8 (one contubernium--no longer 10) came to be called a "decanus." If this is correct, please confirm it. If not, please correct it. If correct, when did the term "decanus" come into usage?

The referenced link doesn't sadly add much, but this is an interesting question and I've been thinking of it alongside the Army Organisation research I've been doing, with particular reference to the Cavalry.

Being gentle, and without simply dismissing Vegetius, it is fairly easy to summarise his approach as being one of harking back to the 'larger' legions of the Republic and Early Imperial times when compared, as he now sees it, to the 'smaller' legio's of the Field Armies (assumed to be around 1,000 men). His entire treatise is from an armchair academic decrying the overall weakening and downgrading of the army, as he sees it, and we can all sympathise given that everything was always better in the 'olden days'.

I see Vegetius with a copy of Polybius by his side - which contains all the information he needs to reconstruct the legion. However, he still wants to 'make things bigger' and, perhaps deliberately it seems, seems to inflate his numbers wherever possible. Thus, in the infantry organisation, he is very keen that his century is 100 men, but, he adds 10 more men (the decanus) by adding one of them for every 10 (making 11), he then goes one further step by adding the Centurion himself - for 111 (a number he obviously likes), rather than the 80+3(?) that we are mostly more comfortable with. He then goes on, with nice consistency, to do something similar with the cavalry, where his 30-man turmae also has 3 commanders for a total of 33.

That then is all preamble; the original, primary and arguably the best source is indeed Polybius. In his expose on the legion he is completely clear in his description of the turmae: 30 men, divided into 3x10 man components, each commanded by a Decurion (inclusive); the senior of which (but still a Decurion) commands the 'Troop' (by far the best translation, Squadron being regularly used for both turmae & alae in various works). [NB - and yes, I do not reference Hyginus for all the best reasons)

As far as I have been able to determine, and I've been looking, there is no real reason for the turmae of 30 (officers including) to have changed at all throughout the Empire, until the later reorganisations of the Byzantine and near-Byzantine period when the 'troop' grew (adding ranks of archer-specialists).

In summary, I don't believe there is any reason why the term decurio didn't indeed apply to a leader of 10 (himself included).

To add final fuel to the fire, I've not really found any particular term to cover the 'senior man' in the 8-man contubernia, but strongly suspect that it existed, and equally believe that he was a one-and-a-half pay man (sesquipilus - 'one-and-a-half spear'(?)); the best modern equivalent being 'Corporal'.

M2CW

[Robert Vermaat]

Being gentle, and without simply dismissing Vegetius, it is fairly easy to summarise his approach as being one of harking back to the 'larger' legions of the Republic and Early Imperial times when compared, as he now sees it, to the 'smaller' legio's of the Field Armies (assumed to be around 1,000 men). His entire treatise is from an armchair academic decrying the overall weakening and downgrading of the army, as he sees it, and we can all sympathise given that everything was always better in the 'olden days'.

I agree. Vegetius is more than once seen to misunderstand numbers. he is our only source for a 10-man contubernium, but he may have derived that number from his idea tha the decanus commanded the contubernium. But as already stated here, the decurion did not command 10 men, the centurio did not command 100 men either.

[Mark Hygate]

...... But as already stated here, the decurion did not command 10 men...

Actually, in it's original Polybian context, and indeed there is no reason to reject the idea that it continued in the turmae-based cavalry and other equites for a long time after (until maybe even ~500AD'ish) - I would actually argue that a decurion was indeed responsible for 10 men, including himself.

A 10-man cavalry scouting patrol I would consider to be a very regular occurrence and even splitting them in two for 2x5-man sections (using his deputy - probably a duplicarius of one form or another.

On the field of battle, however, the senior decurion of the Turmae would be in charge (cf Polybius) and the unit would fight in the classic 3 lines split into their 10-man sections, as is described in the cavalry training manuals.

[Robert Vermaat]

...... But as already stated here, the decurion did not command 10 men...

Actually, in it's original Polybian context, and indeed there is no reason to reject the idea that it continued in the turmae-based cavalry and other equites for a long time after (until maybe even ~500AD'ish) - I would actually argue that a decurion was indeed responsible for 10 men, including himself.

A 10-man cavalry scouting patrol I would consider to be a very regular occurrence and even splitting them in two for 2x5-man sections (using his deputy - probably a duplicarius of one form or another.

On the field of battle, however, the senior decurion of the Turmae would be in charge (cf Polybius) and the unit would fight in the classic 3 lines split into their 10-man sections, as is described in the cavalry training manuals.

being no expert on the early army I was thinking of the infantry, where the contubernium numbered but 8 men. I share the belief that Maurikios' dekarch was not meant as a literal command (neither were his hekatontarch (“commander of a hundred”), pentarch (“commander of five”) or tetrarch (“commander of four”). Are you suggesting that the cavalry decurion commanded ten men, or that every decurion commanded ten men?

[Mark Hygate]

..being no expert on the early army I was thinking of the infantry, where the contubernium numbered but 8 men. I share the belief that Maurikios' dekarch was not meant as a literal command (neither were his hekatontarch (“commander of a hundred”), pentarch (“commander of five”) or tetrarch (“commander of four”). Are you suggesting that the cavalry decurion commanded ten men, or that every decurion commanded ten men?

Yes, no, maybe... :lol:

Actually a 3 part answer/comment then:

1 - Answering the OPs original question, then yes, I do believe the origin (source: Polybius) of the rank 'decurion' comes from someone, in the Roman Cavalry/Equites who lead a section of 10 men (incl).

2 - No, the original intent was that this applied only to cavalry. I strongly suspect that the Roman infantry was organised at the sub-sub-unit level (section) of 8 men (for all the good reasons, indeed, that many armies, the British included, still do). That these men lived and fought as a section of 8 (that being the deepest normal formation throughout the Republic and, certainly, Early Empire periods) - and directly from it's Greek-style antecedents.

3 - Now, later, just as we can all observe throughout history, once a rank is created it tends not to go away. Thus its use, perhaps in a modified form, could re-appear at any almost any level. Now considering Maurikios' usage however, I would suggest that we have to consider a combination (or all) of the likely reasons: either he's using earlier Greek manuals (that they all have - eg Asclepidotus) to help describe his current situation; or using similar terms that are close; or perhaps they are indeed descriptive still and it would be a brave man to positively consider otherwise.

Lastly, the term 'centurio' we all believe doesn't mean he commanded 100, but normally, in the Roman context 80 (or 160 in the case of the expanded 1st Cohort). I do believe, however, that the term is still consistent. The Romans divided their tribes/people, their land and their army into 'centuriae'; none of which necessarily have anything more than a passing relevance to '100'. It, however, comes as no surprise to me to that the 'leader' of such a division is called a 'centurio' though.

{PS - it's no good, I simply must settle down and put my research and conclusions down on paper as I've intended and post it here for all to criticise nicely)

[Robert Vermaat]

Yes, no, maybe... :lol:
Actually a 3 part answer/comment then:
1 - Answering the OPs original question, then yes, I do believe the origin (source: Polybius) of the rank 'decurion' comes from someone, in the Roman Cavalry/Equites who lead a section of 10 men (incl).

Agreed.

2 - No, the original intent was that this applied only to cavalry. I strongly suspect that the Roman infantry was organised at the sub-sub-unit level (section) of 8 men (for all the good reasons, indeed, that many armies, the British included, still do). That these men lived and fought as a section of 8 (that being the deepest normal formation throughout the Republic and, certainly, Early Empire periods) - and directly from it's Greek-style antecedents.

Also agreed.

3 - Now, later, just as we can all observe throughout history, once a rank is created it tends not to go away. Thus its use, perhaps in a modified form, could re-appear at any almost any level. Now considering Maurikios' usage however, I would suggest that we have to consider a combination (or all) of the likely reasons: either he's using earlier Greek manuals (that they all have - eg Asclepidotus) to help describe his current situation; or using similar terms that are close; or perhaps they are indeed descriptive still and it would be a brave man to positively consider otherwise.

I think that Maurikios is being theoretical there. I really don't think that he has sections of 4 and 10 at the same time. But otherwise we indeed see offices changing. One such is the campidoctor, originally responsible for training but evolving into a very important regimental NCO. Same name, different function.

Lastly, the term 'centurio' we all believe doesn't mean he commanded 100, but normally, in the Roman context 80 (or 160 in the case of the expanded 1st Cohort). I do believe, however, that the term is still consistent. The Romans divided their tribes/people, their land and their army into 'centuriae'; none of which necessarily have anything more than a passing relevance to '100'. It, however, comes as no surprise to me to that the 'leader' of such a division is called a 'centurio' though.

So maybe, like the Decurion, he commanded a 100 men. A ducentenarius was riginally a racehorse with two hundred victories (Diocles).

[Renatus]

Lastly, the term 'centurio' we all believe doesn't mean he commanded 100, but normally, in the Roman context 80 (or 160 in the case of the expanded 1st Cohort). I do believe, however, that the term is still consistent. The Romans divided their tribes/people, their land and their army into 'centuriae'; none of which necessarily have anything more than a passing relevance to '100'. It, however, comes as no surprise to me to that the 'leader' of such a division is called a 'centurio' though.

I made the following point in another thread but nobody took me up on it. Varro states that the proper number of men in a century is one hundred (de ling. lat., 5.88), which could give ten contubernia of ten men each. Is he speaking theoretically or from his own military experience, having served with Pompey in Spain against Sertorius and in the Civil War?

[Mark Hygate]

So maybe, like the Decurion, he commanded a 100 men. A ducentenarius was riginally a racehorse with two hundred victories (Diocles).

My belief/deduction (however, see below) for the military 'Centurion' is more based on a name for the 'one-hundredth' division (cf tribal and land divisions - tribal divisions for political purposes are also 'lead' by 'Centurions') and, like the land divisions, are based upon the idea of a 10x10 grid as their fundamental basis. So indeed is the proto-typical (Polybian) Roman army based upon 2 Roman Legions - divided into 100 century-equivalents - each lead by a 'Centurion', but then modified for tactical necessity.

I made the following point in another thread but nobody took me up on it. Varro states that the proper number of men in a century is one hundred .......

I'm sorry I missed it and certainly take no credit for original thought; and am quite sure that others have had similar ones. Our interpretation of history is all simply that, looking back at bits and pieces and never actually knowing.

In this case, there is, of course the other sensible likelihood that, whilst 80 men formed the fighting and tactical strength of a century, then by adding the Optio, Signifer and Centurion himself we are already at 83. It has long been postulated that other members of the legion were carried on the Century's 'books' and it is not difficult to add: Clerks; Medical Orderlies; Quartermasters; Fabricators of various items; and perhaps even Artillerymen (older, perhaps less able) and rapidly get to ~100.

The Cavalry is different - for it doesn't group and march together with any of its support. 10 man sections, 30 man 'Troops' have to be together on their horses and there is little room for extraneous bodies - these would have to be entirely separate.

In summary, and I believe in its original usage, then yes, I believe a Decurion of cavalry lead his 10 man section (the senior also responsible for the organisation of his turmae); for the Centurion he commanded his century (both as a centuriae-division of the army and, most conveniently, probably very near to 100 men total).