LEGION ORGANIZATION and OFFICERS                    6/25/05

       This page summarizes the basic arrangement of a Roman legion, and the officers and command structure.  There are also brief sections on the physical appearance of the Centurion and senior officers.  For the organization of our modern Legio XX, see the Bylaws page.  And as always, for more information consult the books on the Bibliography page.

Organization of the Legion
Equipment of the Centurion
Equipment of the Legatus and Tribunes
Terms of Service

       For the Imperial legion, say from Julius Caesar onwards, the basic organization is like this:

8 men=1 contubernium (mess unit/tentful), probably led by a file leader
10 contubernia=1 centuria (century), commanded by the centurion
6 centuriae=1 cohors (cohort), probably commanded by its senior centurion
10 cohortes=1 legio (legion), commanded by the legatus

       There is more information about the organization of the legion, Republican and Imperial, on Sander van Dorst's Roman Army Page, http://members.tripod.com/~S_van_Dorst/legio.html.  For in-depth analysis of how the legion functioned in battle, see Gary Bruggeman's website of Models of the Roman Legion, http://www.geocities.com/Athens/Oracle/6622.

       During the Republic the centuries had been paired into maniples, each with a "front" and "rear" century.  These terms survive into later times, and that leads into all kinds of arguments about how the units were arranged in battle.  But in the Empire the maniple is apparently no longer used, the cohort being the basic tactical unit.

       By the Empire all the troops are armed and armored pretty much the same way (we think!), and the century is a standard 80 men, all Roman citizens.  In the mid-first century AD some legions changed their first cohort to 5 double-sized centuries, so it had 800 men but only 5 centurions, for a full legion strength of 5120.  (But remember that units are ALWAYS under strength!)  There is also a cavalry contingent of about 120 men, though they are apparently still listed as members of the centuries from which they were chosen, so the total number of troops in the legion is not necessarily increased.  These troops, organized in four turmae of 30 men each, could serve as scouts and messengers, but definitely fought as regular cavalry in battle, being brigaded with the auxiliary cavalry.

       The Legatus was typically a senator in his 30s who had been a senatorial tribune and then gone through the civilian government posts in Rome.  He was appointed by the emperor and held command for three or four years, although some became very good generals and served much longer.  In a province with only one legion, the legatus also serves as governor; in provinces with multiple legions, each legion has a legatus and the provincial governor has command of all of them.

       Second in command of the legion was the tribunus laticlavus or senatorial tribune, a fresh-faced young man on his first job away from home.  He probably relied heavily on the next man down, the praefectus castrorum or camp prefect, a grizzled veteran who had been promoted up through the centurionate.  Then came the five tribuni angusticlavi or equestrian tribunes, appointed from the wealthy class (just below senators).  These men actually had more experience than the higher-ranking senatorial tribune, having just served about three years as independent commanders of auxiliary cohorts.  (Auxiliaries were enlisted from the provinces, and some of them were pretty barbaric.  I wonder if they ever ate their commanders?)  It used to be said that the tribunes just held administrative posts and did not actually lead troops, but now it is believed that each equestrian tribune commanded two cohorts of legionaries.  This would be a logical step up in status from commanding one cohort of auxiliaries.  After a term as legionary tribune, an equestrian tribune could be promoted to command of an auxiliary cavalry ala ("wing", 24 turmae totalling c. 512 men).

       Then come the centurions, 59 or 60 to a legion.  They have their own very confusing hierarchy: There are six distinct steps of seniority in each cohort, from lowest to highest: hastatus posterior, hastatus prior, princeps posterior, princeps prior, pilus posterior, pilus prior.  (Note that "pilus" means "file", NOT the same word as "pilum".  In the Republic the triarii were sometimes referred to as "pilani".)  The cohorts themselves are ranked from the First (highest) to the Tenth (lowest).  In theory a centurion would start in the lowest spot in the Tenth cohort, rise to the top of that, then move to the lowest spot in the Ninth cohort, etc.  Probably it never really happened that slowly.  The centurions of the first cohort were called the primi ordines, and were headed by the  primus pilus ("first FILE"!), the senior centurion in the whole legion.  From there a man could rise to praefectus castrorum, third in command of the whole legion, and after a year in that post he'd retire in fabulous wealth and glory.

       Many centurions, probably most (and probably the best), rose from the ranks by merit (and connections, very important in the Roman world!).  Some centurions, however, were directly appointed by provincial governors from members of the equestrian class.  These were wealthy men who decided to join the army as centurions in order to gain advantages and status, and they were apparently "fast-tracked" for promotion, rising quickly to the highest ranks over the heads of the men of lower social status who had risen from the ranks.

       The centurions formed the backbone of the army's professional officer corps.  It is difficult to draw an exact parallel to modern ranks, but they can be thought of as sort of a cross between a company first sergeant and a captain, and holding ranks as high as a colonel.  While the legatus and tribunes were political appointees, assuring that the army was controlled by men trusted by the Emperor, the centurions were the skilled professional soldiers who would be relied on to run a legion on campaign and in battle.

       At the bottom end of the scale are the milites gregarii, the common soldiers.  After enlistment they spend a couple months in boot camp, then get posted to a legion and spend their first six months rated as recruits (tirones).  The first step up a soldier could make was to immunis, meaning he was posted to some more skilled task (clerical, craftsman, etc.) and was generally "immune" from the usual hard labor and dirty jobs such as road building.  The first real promotion was to pay-and-a-half (sesquiplicarius), such as the tesserarius (guard sergeant), cornicen (horn player), etc.  Next come the double-pay posts (duplicarii), such as optio (second in command of a century), signifer (or is he a sesquiplicarius?), and aquilifer (the Legion's eagle-bearer, a VERY prestigious post!).  Then, hopefully, would come the big step up to centurion.

EQUIPMENT OF THE CENTURION        The centurio or centurion commanded a centuria (century, like a company), which numbered about 80 men during the Empire.  Both words come from the Latin word for "hundred", but in the army the century had ceased to contain 100 men several hundred years before.  Centurions were generally well-respected by their men, if not loved.  They played a crucial role in maintaining the army's strict and often harsh discipline.        The equipment of a centurion was distinctly different from that of his men.  Notably, he wore a transverse crest, meaning that it ran from side to side across his helmet.  It is believed that centurions still wore these crests in battle during the early Empire, while the rest of the troops did not (reserving them for parade wear).  This served as a visual reference and rallying point for their men.  There is little evidence about how colors of crests might have varied according to rank, though there is evidence that either feathers or horsehair were used.        Armor was also different, there being no good evidence that centurions wore the lorica segmentata.  Instead, they wore mail (lorica hamata) or scale armor (lorica squamata), generally about waist length with a curved lower edge in imitation of the classic bronze muscled cuirass.  The historian Vegetius notes that the armor of a centurion was silvered, as well.  Attached to the subarmalis were the rows of flaps called pteruges, generally two rows at the bottom and one or two rows at the shoulder.  It is not known if the pteruges were made of leather or fabric, or what color they might have been, though they are sometimes shown with fringed ends.  The helmet seems to have been of the same general types worn by legionaries, except for the crest and its attachments, and it would probably have been of the highest quality and latest style, and silver-plated like the armor.        Another distinction was the wearing of greaves, often ornate.  They covered the front of the leg from the ankle to above the knee, and were held on by straps and buckles.  The centurion generally wore his sword on the left and dagger on the right, the reverse of most legionaries, though again these weapons would simply be more ornate versions of what the common soldiers carried.  The belt did not have the hanging studded apron in the front.  The final indication of rank was the vitis or vine staff, a swagger stick about three feet long tyically made of grape vine.  It is known to have been used for whacking miscreant soldiers!        Our Legio XX does not yet have a centurion, so the picture at right was borrowed from VRoma.org.  (Yes, it is the same one as shown in Connolly's Greece and Rome at War, but VRoma says that the images from  their site may be used non-commercially.)  For more illustrations, consult some books or other websites.  Dan Peterson, centurion of Legio XIIII Gemina Martia Victrix in Germany, is shown on the cover of his book, Roman Legions Reconstructed in Colour Photographs.  Chris Haines of the Ermine Street Guard is shown on the Officers page of their site, http://www.ESG.ndirect.co.uk/officers.htm.

The dress and armor of the senior officers of the Imperial Roman army was completely different from that of the centurions and troops.  It was based heavily on Hellenistic tradition, and our knowledge of it comes mainly from sculpture and other artwork since very little archeological evidence has survived.  Although the legatus and tribunes were different military ranks, they were all aristocrats, drawn from the same upper social class.  So they wore the same basic equipment, though it is likely that the higher ranks had more heavily decorated armor.  There may also have been differences in the color of certain garments.        The legatus and the tribunus laticlavus, being of senatorial rank, most likely wore the white tunic with the wide purple vertical stripes called clavi which were the symbol of their social status.  The legion's five tribuni angusticlavi would then wear the narrow purple clavi of the equestrian order.  (See Civilian Clothing.)  Shoes may have been the traditional senatorial or equestrian calcei, as appropriate, or an ornate boot decorated with flaps in the form of lions' heads.  A large rectangular cloak called the paludamentum was typically pinned or fixed to one shoulder and often draped or wrapped around the left arm.        Body armor was the classic lorica musculata or muscled cuirass.  It was most probably made of hammered bronze, formed to resemble the muscles of a man's chest.  There were long and short versions of it (the latter much better for riding on horseback!), and some were heavily decorated with embossed designs, and likely silvered or even gilded.  There are no known surviving muscled cuirasses from the Imperial period, but those from the early Republic or pre-Republican eras are strong and functional, not very heavy but very rigid.  The depiction of the muscled cuirass in Roman artwork is always subject to an unknown amount of stylization and artistic convention, more so as the Empire progresses.  Some are clearly shown to be of some flexible material, but not mail or scales.  Others could be interpreted as being rigid, but have no seams or closures.    There remains the possibility that  sometimes the muscled cuirass--or a purely ceremonial item which resembled it in form--was made of leather or fabric of some sort.   For the mid-first century, however, the "safest" interpretation is still polished metal, at least for a cuirass worn in battle.  The best source for more details is Travis Clark's site on Lorica Musculata Resources, http://astro.temple.edu/~tlclark/lorica/.        Officers are frequently shown bare-headed, but it is safe to assume that they all wore helmets in battle.  The Hellenistic "Attic" helmet was typical, and though its general form was similar to what is usually seen in movies, it was also made of polished metal.  Like the muscled cuirass, these helmets were not as evolved and efficient as those worn by the men in the ranks, but would certainly protect if necessary.  The crest was generally mounted directly on the skull of the helmet, not raised up on a knob or support as legionary crests were, and it often seems to be made of rather plumy feathers, as if from an ostrich.

       Instead of the gladius, senior officers are often shown with a weapon called the parazonium, the hilt of which could be in the form of an eagle head, or more like a pugio with a lobed pommel.  It can be slung on a narrow shoulder baldric but is more often simply cradled in the left arm, and the fingers of the left hand can be forked over the lobed pommel.  The plated military balteus was not worn with a muscled cuirass, but there could be a fabric belt or sash with fringed ends, worn rather high, which was tied in a square knot at the front and the ends tucked up in short loops.  Like much of the rest of the officer's gear, this belt is a Hellenistic tradition.  The few depictions of officers with shields show a large round or oval shield.  It is probably safe to speculate that these officers would have their shields carried by a servant in a normal battle, since they were safe behind the lines directing the action.  Only in an emergency would they need to use their shields for personal defence.  Greaves do not seem to have been part of the traditional officer's dress, but no doubt they could be worn in battle if desired.

       That's Gaius Julius Caesar himself above, also from the VRoma.org site.  He wears an ornate long muscled cuirass with the distinctive Roman shoulder flaps (fastened at or above the nipples) and two rows of rounded tabs at the bottom.  Below these and at the shoulders are the pteruges with large twisted fringes.  Also note the tied sash, and the lack of helmet and greaves.  For more images of higher officers and muscled cuirasses, see http://rubens.anu.edu.au/student.projects97/armour/muscle/muscle.html.

       The famous Louvre Relief can be seen at http://rubens.anu.edu.au/student.projects97/armour/muscle/muimage/MU1.html and http://www.livius.org/a/1/romanempire/praet_guard.jpg.  While this is often said to portray Praetorians, what it actually shows is OFFICERS, Praetorian or otherwise.  The unarmored man at the right of the front row could be a lower-ranker, because of his lack of armor and belt with apron, but the other two figures in the front rows are wearing the muscled cuirass which marks them as aristocrats.  NOTE--the heads of the three men in the front row are early modern replacements!  Those men might not have been wearing helmets at all, originally.  (The helmets are pretty much copied from those in the rear rank, however, so they are not necessarily inaccurate as such.)  Also, the entire middle third of the man at far left is a restoration, which explains the odd lower edge of his cuirass and the bizarre belt.

       From the beginning of the Republic in 506 BC until about 100 BC, Roman legionaries were supposed to be landowners.  This meant that they had enough income to equip themselves properly, and that they had a vested interest in fighting for Rome.  Equipment was not supplied by the state, so any man who could not afford a certain minimum of gear was exempt from military service.  Eligible men were drafted for service in the spring, and in the fall the army was disbanded and the men sent home.  Any particular man might or might not serve in successive years, and he was required to serve in a total of ten campaigns before reaching the maximum age of enlistment.  This made for a citizen army with no permanent units.  By c. 100 BC, though, Rome's foreign holdings had spread, while the number of small farms (and their owners) had declined.  In order to make up for the resulting shortage in manpower, Rome began to recruit non-landed and poor men into the army, equipping them at government expense, increasing their pay, and often promising them a land grant upon discharge.  This marked the beginning of a change from a part-time citizen army to the full-time volunteer professional army of the Empire.

       All legionaries were required to be Roman citizens, though this did not mean that they were of Italian ancestry.  Citizenship was spreading through the provinces during the late Republic, and this accelerated in the early Empire as discharged auxiliary troops were often granted citizenship, which they passed on to their children.  By the middle of the first century AD, nearly half of all legionaries were non-Italian, though the proportion may have been higher in the East, where it was common to grant citizenship to potential recruits upon enlistment.  By the reign of Hadrian, Italians made up only about 5 percent of all legionaries.

       At the beginning of the Empire, the term of enlistment was supposed to be 16 years, though there was no regular system of discharges and men were often kept beyond their nominal retirement point.  This rose to 20 years, plus five years in the reserves, by the time of Claudius.  Vespasian made the term of service a flat 25 years, though discharges still seem to be given only every other year.  Soldiers were forbidden to be legally married while serving, though of course many had local girlfriends, common-law wives, and children.  Upon discharge, a soldier's "marriage" was recognized as legal, and any children he had were recognized as legitimate and Roman citizens.  This is not only a nice "perk", since illegitimate children of civilians generally could not become citizens, but it also made a growing recruiting pool for the legions.  A steadily increasing number of recruits listed their place of origin as "in castris", "in the camp", meaning their fathers had been soldiers (not necessarily that they had actually been born and raised in a military fortress!).