Roman legions -- frontage and depth
JMeun18203
I need some help with some basic numbers on Roman legions -- Marius
through early Republic period.
What was the typical manpower and deployment depth of a cohort?
What frontage and depth would a fully deployed legion take up?
Were artillery pieces integral to the legions and used in open battles, or
were the assigned to the baggage train and used only in seiges actions?
Thanks.
John Meunier
John Meunier
Owensboro, Ky.
Dan Dionne
JMeun18203 wrote:
>
> I need some help with some basic numbers on Roman legions -- Marius
> through early Republic period.
>
> What was the typical manpower and deployment depth of a cohort?
>
> What frontage and depth would a fully deployed legion take up?
>
> Were artillery pieces integral to the legions and used in open battles, or
> were the assigned to the baggage train and used only in seiges actions?
John,
I assume you mean through the early Imperial period?
The manpower of a cohort varied more than you might expect. The figures
I've seen most often are a standard strength of 360 or 480, with the 1st
cohort generally having more than that, up to about 600. Standard depth
of deployment would be six or eight. I think the frontage per man was
only three feet. Sorry I can't cite any sources right now--this comes
from memories of Caesar and Tacitus.
Artillery pieces are a bit puzzling. I've seen wargaming sources that
claim they were used in open battles, but I recall no such mention from
any primary source. I think they were assigned to the legion, but only
deployed in camp and for sieges. I'd be happy to be proven wrong, as I
must confess I use my late Eastern Imperial artillery on the
battlefield.
--Dan Dionne, ddi...@us.ibm.com
Michael Childers
In article <19970916203...@ladder02.news.aol.com>,
jmeun...@aol.com (JMeun18203) wrote:
> I need some help with some basic numbers on Roman legions -- Marius
> through early Republic period.
>
> What was the typical manpower and deployment depth of a cohort?
>
> What frontage and depth would a fully deployed legion take up?
>
> Were artillery pieces integral to the legions and used in open battles, or
> were the assigned to the baggage train and used only in seiges actions?
>
This is a long time period with several changes in 'doctrine'.
As with any field army strengths will vary. Papyrus rolls for units
stationed in Egypt (c. 100 ad, I think) show some centuries with 100+ men,
though the commonly accepted strength for a century is 80 men (there
being 6 centuries in a cohort). The commonly accepted field strength for
a legion appears to be 4500 to 5400. The latter strength would only be
approached after the first cohort was converted to 5 double strength
centuries (c. 25 ad).
For deployment, again you get a lot of variation. The typically accepted
arrangement is 80 files by 6 ranks, with each man being c. 5 ft from the
next. Obviously the cohort could close up (c. 27 in. between men) to use
their spears if necessary. The testudo was much tighter even than that.
Legion deployment was even more variable, being dependent on the tactical
situation. (As a side note van Creweld contends that the legion was an
administrative unit, like the regiment in the 18th century, not a tactical
unit.) A fairly typical deployment would be a checkerboard affair 3
cohorts deep and c. 4 wide. Osprey has an interesting diagram in their
book on "Republican to Early Imperial Roman Armies".
There is no clear info on the artillery, but appearently it was deployed
both ways depending on the tactical situation. The clearest indications
that I've seen seem to indicate that mostly the artillery was left in the
camp, emplaced on the 'walls'.
There are numerous secondary sources, but very few primary sources from
the Roman period. A lot of the thinking is logical supposition based on
archeological info and inferences from the few primary sources.
If this helps and you want more info e-mail me direct. I check the news
groups on an erratic basis.
Scott L Karakas
John,
Gaius Marius is a figure from the Late Roman Republic, living c. 157-86
B.C. Did you perhaps mean the early Imperial period?
JMeun18203 (jmeun...@aol.com) wrote:
: I need some help with some basic numbers on Roman legions -- Marius
: through early Republic period.
: What was the typical manpower and deployment depth of a cohort?
: What frontage and depth would a fully deployed legion take up?
: Were artillery pieces integral to the legions and used in open battles, or
: were the assigned to the baggage train and used only in seiges actions?
: Thanks.
JMeun18203
Yes, yes. I meant Early Imperial not Early Republic.
Do we have any idea how much space would be left between lines? I gather
two lines or three lines of cohorts were common. How far back would the
supporting lines of cohorts be deployed?
If they are fairly close, you could easily represent two lines within what
most wargames rules call the same unit. In WRG 7, for instance, assuming a
6 to 8 ranks of depth is represented by 2 elements depth on the table top,
then two cohorts, one directly in front of the other -- four elements deep
-- cover 80 yards of ground at scale.
If the two lines of cohorts historically lined up within 80 yards of each
other, then the historical representation would be a formation of whatever
frontage by four elements deep, rather than two independent lines of 2
element deep cohorts.
Maybe this is all navel gazing, but it is something I have wondered about
how to correctly represent for some time.
John Meunier
Owensboro, Ky.
Scott L Karakas
John,
Thanks for the clarification. One reason that a truly definitive answer
would be difficult is that the surviving ancient sources don't go into
that sort of detail. Some, like Caesar, assumed that the audience he was
writing for (contemporary Roman senators and knights, for the most part)
was familiar with these details. Others, like Tacitus, are interested in
other things. Shame on them for not knowing that some of us would be so
interested in these details! ;-)
That having been said, modern scholars have tried to recreate Marian and
early imperial formations from those hints which are available. The
most convincing, IMHO, is that the "Marian" cohort was created by
combining one maniple each of the old velites, hastati, principes and
triarii. From Tacitus, we know that an imperial cohort had 480 men,
divided into six 80-man centuries (the old maniples?). However,
excavations of early imperial forts and camps indicates that, at some
point (perhaps under the Augustan reorganization of the legions?), the
first cohort was grouped into five double-sized (160 man) cohorts. Thus a
ten-cohort Marian legion would have a paper strength of 4800 men, while an
early imperial one would have about 5120, not counting the 120 cavalry
also included under Augustus. Each cohort was also assigned a number of
small bolt-throwing scorpiones and large stone-throwing ballistae, but
no written source mentions them being used in the field, only during
sieges.
As to battlefield dispositions and frontages, the most convincing
arguments I've seen arrange the ten cohorts of a legion in three lines,
4-3-3. Assuming that each cohort is eight lines deep, and that each
legionary has a 1-yard frontage, one 480-man cohort would have a frontage
of 60 yards (100 yards for the oversized first cohort. If you assume that
the legion is arranged in a "checkerboard" pattern, with enough space
between the front-line cohorts to allow the second-line ones to come up
in between them, the legion would occupy a frontage of approximately
420-460 yards. On the other hand, if you assume that the cohorts of the
first line are spaced closely together, with the other cohorts directly
behind them, then the legion frontage would be only 240-280 yards.
Caesar's eight understrength legions at Pharsalus (21,000 men total)
apparently occupied a frontage of about 1200-1500 yards. No sources give
us any clue as to what the depth of a legion was, or how much space would
have existed between the three lines of cohorts,
I hope that this fairly answers your questions. As you can see, there is
a lack of definitive evidence on this subject, which leaves a lot of room
for individual speculation and interpretation. As a good starting
secondary source, I would recommend _The Making of the Roman Army: From
Republic to Empire_ by Lawrence Keppie (1984). Good luck in your
research, and good gaming!
Scott
Ross Macfarlane
Dan Dionne wrote:
> any primary source. I think they were assigned to the legion, but only
> deployed in camp and for sieges. I'd be happy to be proven wrong, as I
> must confess I use my late Eastern Imperial artillery on the
> battlefield.
>
> --Dan Dionne, ddi...@us.ibm.com
The only one I can think of without looking anything up,
was Someone or other's Order of battle against the Alans from
a 3rd? Century source or maybe later, where it was proposed
that the artillery be posted on a hill behind the infnatry to be
able to fire overhead, I haven't read this for a decade or so hence its
a little fuzzy but in nay case this was a recommended plan not an after
action account.
Loch Sloy!
- Ross
Scott L Karakas
Ross,
I think you are referring to the Greek historian Arrian. He lived
sometime around AD90-160, and was governor of Cappadocia under Hadrian.
In his description of his campaigns against the Alani, he gives an order
of battle which includes using ballistae in the way that you describe. I
had forgotten about this example in my earlier post. Mea culpa! Mea
culpa! Mea maxima culpa! 8-P
Scott
Ross Macfarlane (rma...@auracom.com) wrote: