Decurions and Centurions

[Jack]

Hello everyone,

I've got a question about the make up of a Roman legion. I'm certain I've read this somewhere but I don't know where, maybe wikipedia but I've just spent hours searching and can't find it again, can anyone help?

If a Decurion was an auxiliary cavalryman, was there the rank of centurion in a Roman cavalry squadron?

I thought there was and he had an optio and a troop of men like a tent party.

Cheers John

[Nathan Ross]

A decurion was actually the commander of a cavalry turma, which comprised 32 men. 16 turmae made up an ala, or wing, which was commanded by an equestrian praefect. The decurion was therefore somewhat similar in role to a centurion within a legion (although of lower status, as he was an auxiliary), or an auxiliary cohort. The cavalry equivilent of the optio would be the duplicarius (double pay man).

[Jack]

Cheers Nathan,

Yes your right about the decurion. What I'm trying to confirm (or deny) is that centurions and optio's made up the cavalry squadrons as opposed to the normal cavalry auxiliary turma within a legion.

The usual (mass) of cavalry weren't full time legionaries after sometime in year dot BC but a small detachment, something like 220 men I'm sure, were regular troops. Either that or I've made it up! hock:

I'm just wondering if somebody knows for sure?

John

[Nathan Ross]

I'm not sure if I understand what you're asking here, John! :wink:

The cavalry detachments within the legion (equites legionis) were not auxiliaries, but citizen legionaries seconded from their usual cohorts. We know little about their command structure, organisation, or even purpose - there's no mention of either decurions or centurions commanding them, although an optio equitum does turn up in the early third century. Perhaps this was what you were thinking of?

The cavalry 'squadrons' (alae) were comprised of auxiliaries, so separate from the legions. They had decurions, but no centurions or optios.

[Jack]

Cheers Nathan, that sort of answers the question, thank you. Do you know anything of the existence of mounted centurions and or optios on scouting, messenger or special duties? For example where a Legate wanted a task done but didn't necessarily trust the auxiliaries to do it and so would have a section of mounted troops for special purposes?

[Jack]

I think I've found what I was looking for:

Equites Legionis; These were the cavalry units attached directly to the Legion and were considered regular legionaries of immunes rank. Originally they consisted of 120 men but may have been upwards of 1,000 like the Ala Millariariae. Generally this unit would fall under the command of a centurion or optio.

[Jack]

Nathan, I found it at unrv.com thanks for your help. :wink:

[jvrjenivs]

Do you know anything of the existence of mounted centurions and or optios on scouting, messenger or special duties?

Well, the Roman army had a whole intelligence aparatus. Do a search for the Speculatores and Exploratores. There have been some topics on them on RAT already

[Nathan Ross]

Equites Legionis; These were the cavalry units attached directly to the Legion... Generally this unit would fall under the command of a centurion or optio.

Ah yes - I mentioned these in my second post above - sorry, I was assuming you knew about them already! :wink:

There's no evidence, as far as I know, for centurions commanding them though - there were sixty centurions in the legion, one for each century, so more would be needed if the legion cavalry were a regular centurion's command. But I'm sure a centurion could have been detached to lead them if necessary...

There was a discussion here a while back about whether centurions were mounted - even if they weren't, some would certainly have owned horses, and those directly commissioned from the Equestrian Order would have had their own mounts.

Do you know anything of the existence of mounted centurions and or optios on scouting, messenger or special duties?

As Jurgen says, the exploratores and speculatores were the usual scouts for the army. There are plenty of cases where centurions were sent off on 'special missions' though. Many of these men were probably Praetorian centurions, who were given official assignments on Imperial business, but in the provinces a legate or governor would have used the legion centurions available in a similar way.

One example: during Trajan's conquest of Parthia, a centurion (probably Praetorian) named Sentius was sent to the fortress of Adenystrae to demand the surrender of its ruler, the Parthian client king Mebarsapes. The king refused, and threw Sentius into the fortress dungeons. Sentius not only escaped from captivity, but led a rebellion of his fellow prisoners, captured the fortress and opened the gates to the advancing Roman army! (Cassius Dio LXVIII.22)

[Jack]

Thanks Jurgen and Nathan :wink: