Legionary Ranks

Aside from the rank and file legionary who received the base wage of 10 assēs a day or 225 denarii a year (see Pay), the following describes the system of ‘officers’ that developed within the legions from the Marian reforms (104 BC) until the military reforms of the Emperor Diocletian (c. AD 290).

Attempts to align the ranks of the Roman army with its modern descendants is fraught with problems. There are some parallels at the higher levels of command but as one descends the rank structure, the roles and responsibilities increasingly diverge or simply do not correlate.

Senior officers

Legatus Augusti pro praetore (or “Imperial Legate”) commanded two or more legions. As the Imperial Legate he also served as the governor of the province in which the legions he commanded were stationed. Of senatorial rank, the Imperial Legate was appointed by the Emperor and usually held command for 3 or 4 years. In modern parlance, an Imperial Legate would be called a General.

Legatus legionis (or “Legion Legate”) was the commander of each individual legion. The post was usually filled by a senator, appointed by the Emperor, who held command for 3 or 4 years, although he could serve for a much longer period. In a Roman province with only one legion, the Legatus was also the provincial governor. In such circumstances, the Legatus was both Legion Legate and Imperial Legate. The Legatus also served as commander of the auxiliary units attached to the legion though they were not formally a part of the legion's command structure.

Tribunus laticlavius (or “Broad Band Tribune”) was so named for the broad striped tunic worn by men of senatorial rank. Such tribunes were appointed by the Emperor or the Senate. Though generally young, he was more experienced than the tribuni angusticlavia. He served as second-in-command of the legion, subordinate to the Legatus, and would take command of the legion should the Legatus die. That said, because of their age and relative inexperience, Tribunus laticlavii were not the actual second-in-command in battle.

Praefectus castrorum (or “Camp Prefect”) was third-in-command of a legion. He was typically a long serving veteran from a lower social status than the tribunii whom he outranked, and who previously had served as primus pilus and finished his 25 years with the legions. He was used as a senior officer in charge of training a legion, though he could also command an auxiliary cohort.

Tribuni angusticlavii (or “Narrow Band Tribunes”) were the five lower ranking tribunes in a legion. They were normally from the Equestrian class and had at least some years of prior military experience. Tribuni angusticlavii often served in the role of administrative officers. This tribunate was often a first, but optional, step in a young man's political career known as the cursus honorum.

Primus Pilus (meaning “first file” or “first spear”) was the most senior centurion in a legion. He directly commanded the first century of the first cohort and commanded the whole first cohort when in battle. As one of the most experienced officers, the Primus Pilus was also a senior advisor to the Legatus. The senior centurion was paid sixty times more than the soldier’s wage and was guaranteed elevation to the Equestrian class on retirement.

Field rank officers

Centurio (or “centurion”) was one of the 59 mid-level officers who commanded the centuries in the legion’s 10 cohorts. The centurions were the backbone of the professional army, the career soldiers who ran the day-to-day life of the soldiers as well as issuing commands in the field. With so many grades, centurions had particularly good prospects for promotion. Centurions were typically promoted from the ranks, but in some cases they could be directly appointed by the Emperor or other high-ranking officials. Centurions were paid ten times the basic soldier’s wage.

The First Cohort was divided into five double-sized centuries. The five centurions of this cohort were known as the Primi Ordines and outranked all other centurions in the legion. Within the primi ordines the ascending order was as follows: Hastatus posterior, Princeps posterior, Hastatus, Princeps, and Primus Pilus. Excluding the Primus Pilus, these four centurions were paid thirty times more than the base wage. They were also senior to all other centurions save the Primus Pilus and each Pilus Prior of Cohorts Two to Ten.

In any legion its cohorts were ranked from First to Tenth such that the First Cohort, with its five double-sized centuries, took precedence over all others. The six centuries within each of the other nine cohorts were similarly ranked from one to six. Thus, the Century that each Centurion commanded was a direct reflection of his rank and status. Command of the First Century of the First Cohort (that commanded by the Primus Pilus) was the highest and the Sixth Century of the Tenth Cohort the lowest.

The centuries were named after the three battle lines of the earlier manipular legion, which used three classes of soldier: hastati, principes and triari [1]. Each of the three titles was sub-divided within the century to create a forward and a rearward century. Accordingly, the centurion ranks reflected this being named hastatus, princeps and triarius (albeit under its alternative title of pilus). Thus, the six centurions in Cohorts Two to Ten held the ranks of, in ascending seniority, hastatus posterior, hastatus prior, princeps posterior, princeps prior, pilus posterior and pilus prior.

Within the second to tenth cohorts, the commander of each cohort's first century was the Pilus Prior, making them the senior centurions of their respective cohorts [2]. These positions were usually held by experienced veteran soldiers who had been promoted from within the ranks. In battle, the Pilus Prior commanded their entire cohort.

Principales (junior officers?)

Below the centurionate were the Principales, which included the optiones and signiferi (standard-bearers; the -fer in signiferi comes from ferre, the Latin “to bear” or “to carry”).

Optiones

Optio centuriae, each Centurion’s second-in-command. Optiones were appointed by their Centurion from within the century’s ranks and as a duplicarius were paid twice the standard legionary wage. The term Optio centuriae means “chosen man of the century”.

An optio was stationed at the rear of the ranks to keep the troops in order. To ensure discipline in the ranks he would carry a hastile, a staff roughly as tall as the optio himself, which can be used to dress the ranks or push men forward. Their duties would include enforcing the orders of the Centurion, taking over the Centurion's command in battle should the need arise, supervising his subordinates, and a variety of administrative duties. Optiones were the men most likely to replace the Centurion if the position became vacant.

Signiferi (Standard-bearers)

Aquilifer, the one soldier entrusted with care and protection of the legion's Aquila (“eagle”). The aquilifer's position was accordingly one of enormous prestige, thus he was ranked immediately below the centurions and above the optiones, receiving twice the pay of an ordinary legionary. Losing the aquila was considered the greatest dishonour a legion could endure so the post demanded an experienced, reliable, and trustworthy veteran, with an excellent understanding of the tactics of the legion.

The Aquilifer was very easily recognizable not only because of the eagle standard but because they wore a distinctive lion fur cape. This was worn with the head of the animal strapped to the helmet of the bearer. Carrying the legion’s eagle aloft, which necessitates using both hands, prevented the Aquilifer from wielding the large rectangular scutum (shield) of his fellow legionaries. Like the other signiferi, he instead carried a small circular shield called a parma equestris that could be slung from a baldric over one shoulder.

Imaginifer carried the imago, a three-dimensional portrait made from beaten metal, bearing the image of the Emperor as a constant reminder of the troops' loyalty to him. A special position from the time of Emperor Augustus onwards, the Imaginifer was paid twice the basic wage.

Signifer was the Century’s standard-bearer entrusted with carrying the signum, a spear shaft decorated with medallions and topped with either a spearhead or an open hand signifying loyalty. Each century had a Signifer, thus there were 59 in a legion, and within each cohort the first century's signifier would be the senior. In addition to carrying the signum, the Signifer also assumed responsibility for the financial administration of the century and functioned as the legionaries' banker. In so doing, the Signifer had to be able to write and calculate well which, allied with his veteran’s experience, were two skills that could see him promoted to the rank of Centurion.

The task of carrying the signum in battle was dangerous. The standard was not only of tactical relevance, acting as a rallying point for the soldiers and possibly a means to indicate battlefield commands, but it was also a desired spoil of war. If the Signifer, or more correctly, the signum, was lost in battle, then the whole century was dishonoured. So, not only did he have to survive in battle while handicapped by the standard, the Signifer also had to stand his ground in or close to the front rank and inspire the soldiers of his century by his steadfastness. Not only that but, like the Aquilifer, he was only able to protect himself with the small parma equestris. The Signifer’s job was quite challenging and thus he was paid double the basic wage.

As with the Aquilifer, the Signifer was particularly noticeable amongst the legionnaires wearing a bear fur cape over his armour. The taxidermied head and the upper jaw of the bear were attached to the Signifer’s helmet while the remainder of the pelt hung down his back. The front paws were draped over his shoulders and tied or pinned together across the Signifer’s chest.

Cornicines were the trumpeters who worked hand-in-hand with the Signifer drawing the attention of the men to the century’s signum and issuing the audible commands of the officers. As a duplicarius the cornicen was paid twice the basic wage.

Vexillarius, or vexillifer carried, as his name implies, the vexillum, a military standard displaying the name and emblem of the legion. This standard consisted of a woven fabric banner, hung on a crossbar attached to a pole or lance, used by both infantry and cavalry. Vexillarii dressed the same as their legionary comrades but, as with the other signiferi, wore a distinctive wolf pelt attached to their helmets. In this way he looked fearsome enough to be able to bear the religiously worshipped insignia as a symbol of the entire legion.

To confuse things, the term vexillarius may also have been applied to any soldier serving in a temporary detachment or vexillatio, away from their parent unit. Furthermore, vexillarius may also have referred to specially re-enlisted veterans. They were so named because these men served in a vexillatio under their own vexillum within but separate from the ordinary legionaries of the legion. Vexillarii had privileged status and were exempt from most basic duties other than combat or those other special skills they may have supplied.

Other specialised ranks (Sesquiplicarii)

Tesserarii, literally the one officer from each century responsible for the daily watchword. They acted as support to the Optiones and were possibly in charge of those on sentry duty or in fatigue parties. The Tesserarius fought as a normal soldier but because of their extra duties were also a sesquiplicarius being paid one and a half times the basic wage.

Immunes were legionary soldiers who possessed specialised skills excusing them from routine labour and guard work. Engineers, artillerymen, musicians, clerks, quartermasters, drill and weapons instructors, carpenters, hunters, and medical staff were all immune soldiers. Regardless, these men were still fully trained legionaries and were called upon to serve in the battle lines when needed.

Evocati were veteran soldiers in the Roman army, who had served out their time and obtained their discharge (missio), but had voluntarily enlisted again at the invitation of the consul or other commander (Cassius Dio, XLV.12). There appears always to have been a considerable number of evocati in every army of importance; and when the general was a favourite among the soldiers, the number of veterans who re-joined his standard would of course be increased. The evocati were, doubtless, released, like the immunes, from the common military duties of fortifying the camp, making roads, etc. (Tacitus, Annals, I.36). As veterans they held a higher status in the army than the ordinary legionaries. Given their experience it seems reasonable that many evocati may have been promoted to the rank of centurion, but that is not to say that all evocati held the rank of centurion or were classed as equivalent to centurions.

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Endnotes:

1. The hastati and principes were soldiers in the prime of life who formed the main strength of the Manipular Legion. The hastati formed the front line and the principes the second. Triarii were the veteran soldiers of the army. They formed the rear rank but were seldom brought into battle. A Roman expression “the battle came to the triarii” was used to describe a desperate situation. ▲

2. Perhaps confusingly it should be remembered that the most senior of all the centurions within the legion, the Primus Pilus, was also a Pilus Prior. ▲

References:

Cassius Dio, Roman History, Book XLV, 12.

Tacitus, Annals, Book I, 36.