Quote: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