History of the Roman Legionary: From Circa 1st Century BC – 3rd Century AD

Roman legionary

Previously, we discussed in detail about the Early Roman army (753 – 146 BC) and how it evolved into the organized Roman legions that we perceive in both popular history and culture. To that end, much has been said about the arms, armaments, and tactics of the famed Roman legions. However, beyond the scope of just glorious battles and momentous results, there was a deeper intrinsic, humane side to the men who formed these legions – that was at once similar (and yet different) with cultures we can identify with. So without further ado, let us take a gander at the history of the renowned Roman legionaries, who were arguably at their effective best from circa 1st century BC till 3rd century AD.

*Note – The article is divided into two sections – with the first section dealing with the typical Roman legionary (from circa 1st century BC – 1st century AD), and the second covering the Imperial Roman Legionary (from circa 2nd century AD – 3rd century AD).

The Roman Legionary: From Circa 1st Century BC – 1st Century AD

Rural Folks Were Preferred In The Legions –

In a generalized scope, all Roman men aging between 17 and 46 were liable for military service – though, the peak age for enlistment tended to be skewed towards the early 20’s age group. And interestingly enough, as historian Ross Cowan noted, each legionary had to claim his origo (origin) from a city or at least a town. However, in spite of such claims, the vast majority of the legionaries came from a rural background.

As a result, their city-based origo credentials were often fabricated during the time of enlistment, usually by the officials themselves. This tendency to ‘make up’ credentials had the Roman style of reasoning – since the rural folks were considered to be more hardy with higher levels of endurance. Moreover, they were also considered to be more dependable with their simplistic character, given their (presumed) unfamiliarity with the sleazy side of urban life. As Vegetius said (in his Epitoma Rei Militaris treatise), sourced from the Roman Legionary 58 BC-AD 69 by Ross Cowan-

They are nurtured under the open sky in a life of work, enduring the sun, careless of shade, unacquainted with bathhouses, simple-souled, content with a little, with limbs toughened to endure every kind of toil, and for whom wielding iron, digging a ditch, and carrying a burden is what they are used to from the country.

In some cases, the romanticizing of country life was stretched to such a degree that even mutinies in the army were squarely blamed on ‘soft’ city-bred recruits (as was done by Tacitus). And since we brought up the ‘character’ profile of a legionary, after being selected for the army, the young man (usually in his late teens or early twenties) had to go through a period called probatio. During this time, both his character and medical condition were heavily scrutinized by enlisting officers. Suffice it to say, the perceived ‘immoral’ recruits (like thieves and such) were weeded out and banished from the army.

Roman Citizenship Was Not A Requirement (But Free Birth Was) –

Contrary to our popular notions, a Roman legionary was not always a Roman citizen (though he was supposed to be, at least ‘in papers’). This law-bending scope was a practical outcome of the civil wars that plagued the Roman realm during the end of the Republic era. For example, Julius Caesar raised the legio V Alaudae from the native Gauls and later naturalized their citizenship. Even during the tumultuous period of the latter part of the 1st century BC, Marc Antony didn’t have access to the major recruitment grounds of Italy.

As a desperate solution, he started filling his army ranks (consisting of around 23 legions) from the native population of the eastern provinces Syria and Egypt. So simply put, oftentimes Roman citizenship was not a requirement, but rather a status that was conferred upon the Roman legionary during his time of enlistment. However free birth was still a requirement, with slaves being barred from the career of soldiery – though they might have been inducted as supporting units inside a legion used for menial works (see entry 9).

Moreover, while the legionaries were supposed to be volunteers who joined the army, many of them were simply conscripted into the legions – due to the requirement of higher manpower during the civil wars and the later Augustan period. There was one particular instance (according to Tacitus) when Emperor Tiberius wanted to tour the entire Roman countryside in a bid to conscript new recruits to fill up the positions of the discharged veterans. The ruler was keen on taking this drastic step due to a lack of volunteers who would join the legions.

Legionary Training Was Rigorous –

Roman legionary

The green recruits who were successfully enlisted as legionaries had to go through a training period of 4 months. During this training ambit, each soldier was given the unenviable task of marching 29 km (18 miles) in five hours with regular steps, and then 35 km (21.7 miles) in five hours with faster steps – all the while carrying a backpack that weighed 45 lbs (20.5 kg).

This weight was intentionally allotted for increasing the endurance level of a Roman legionary and thus added to the overall weight of the panoply worn by the soldiers in their full gear (the weight of the lorica segmentata armor alone might have gone beyond 20 lbs). As expected, the ‘slowpokes’ were severely beaten by centurions and officers with their staffs. Interestingly enough, many of the similar ‘regimens’ are preserved through our modern military culture – with elite forces of some countries trained via the rigorous boot camp methods.

In any case, after the strenuous marching scope was perfected by the legionaries, they were then drilled in battlefield maneuvers (including the hollow square, wedge, and the famed testudo formations) and signaling. Finally, they were trained in weapons handling and in some cases also swimming. Interestingly, the faux swords and shields used in practices were made of wood and wicker, but they weighed twice the mass of their actual counterparts – so as to acclimatize the Roman legionary with fatigue and weariness that could happen in the heat of the battle. In consideration of this incredibly rigorous ambit, the words of Vegetius ring true –

We see no explanation of the conquest of the word by Roman people than their military training, camp discipline and practice in warfare.

Pay and Length of Service Often Resulted in Discord –

Roman legionary
Illustration by Peter Dennis. Credit: Warlord Games Ltd.

During the latter part of the 1st century BC, Augustus followed the guidelines of the preceding centuries and officially formalized the length of service of a Roman legionary to 16 years (in 13 BC). But it should be noted that even after 16 years of service, he was expected to join the vexillum veteranorum or unit of veterans for four more years – (see entry 9).

However, by 6 AD, the initial length of service was increased to 20 years, and it was complemented by the praemia militare (or discharge bonus), a lump sum that was increased to 12,000 sesterces (or 3,000 denarii). And by the middle of 1st century AD, the service was further extended to 25 years. Now beyond official service lengths, the protocols were rarely followed at times marked by wars. This resulted in the retention of the legionaries well beyond their service periods, with some men fighting under their legions for over three to four decades. Suffice it to say, such chaotic measures frequently resulted in mutinies.

As for pay, other than the lump sum of praemia militare, a basic Roman legionary was paid 900 sesterces per year (paid in three installments). This pay scale remained the same until at least 80 AD, in spite of presumed inflation. However, the pay differed for the various units in a legion, with under-officers and specialists being paid one-and-a-half or twice the basic pay grade.

And furthermore, this pay figure was only a nominal value from which various deductions were made in accordance with the goods (like food, equipment, attire and even burial fees) consumed by the legionary. Still, there were cases when the Roman legionary was paid less than he deserved, and sometimes the ‘swindling’ measures were initiated by giving the soldiers worthless parcels of land instead of the praemia militare.

The Lure of Plunder –

Roman legionary

On the other hand, many potential recruits were still drawn to the prospect of joining a legion because of the booty factor. In fact, many charismatic commanders touted the apparent prevalence of loot (and its ‘fair’ distribution), especially when conducting wars against the richer and powerful neighbors – and this ‘system’ was adopted even during the Late Republic era. According to Cicero (as noted by Ross Cowan), this might have been the prime factor that motivated the disparate troops under Marc Antony. The popular practice also alludes to the penchant for plundering – with the soldiers tending to strip the dead as the very first act after achieving victory over their foes.

The Roman legionaries were also not beyond the ‘barbarism’ that is often attributed to their opponents. For example, after stripping the dead, it was a Roman custom to make a trophy from the numerous arms taken from the enemy. During certain times, these erected trophies took the grisly route by comprising enemy corpses and heads that were piked atop raised platforms. Caesar himself attested to such a ghastly practice when his troops defeated the fellow Roman Pompeians outside the settlement of Munda (as mentioned in The Spanish Wars) –

Shields and pila taken from among the enemy’s arms were placed to serve as a palisade, corpses as a rampart. On top, impaled on sword points, were severed human heads.

Male Bonding and Cooking –

Roman legionary

Beyond discipline and training, one of the crucial reasons for the effectiveness of a Roman legionary was directly related to his sense of fraternity within a century (made of 80 men). On a deeper level, a century (centuria) was further divided into ten contubernium (a ‘tent group’, each consisting of eight members). Such classifications basically led to a behavioral aspect of comradeship among the tent group who fought, dined and rested together in their military careers spanning over decades. This sense of identification often translated to high morale and protectiveness on the part of the legionaries when fighting in an actual battleground.

Interestingly, the contubernium was not just limited to the bonding exercises. The Roman army also pushed forth the tent group as a mess ‘team’. These grouped soldiers were expected to cook their own meals and eat them together (while the cost of food was deducted from their salaries). Simply put, the absence of mess halls and catering services rather solidified the bond between the legionaries who had to depend on each other even for peaceful meals.

Cowardice Was Met With Severe Punishments –

In our modern context, the very term ‘decimation’ pertains to the utter destruction of habitat, populace or even an eco-system. But as it turns out, a few Roman generals purposefully enacted the method of decimation as a disciplinary punishment for their legions! To put things into perspective, the word decimation comes from Latin decimatus, and itself relates to decem or tenth. So when the punishment was enforced, it was most probably known as decimatio and the vicious process entailed choosing every tenth man from a cohort (approximately 480 men) to be put to death. And the utterly ruthless part was – this unlucky man had to be stoned or clubbed to death by their remaining comrades-in-arms, in a brutal practice known as the fustuarium.

The remorseless (and very rare) punishment was usually reserved for the troops who have displayed insubordination, cowardice, will to conspire, murderous intent on fellow soldiers, participation in espionage activities, desertion or in few cases when they had faked illness so as not to participate in upcoming battles.

And in a true Roman fashion, the ‘democratic’ part of the severe process encompassed the selection of the soldier in a random manner (by lottery) – regardless of his rank, reputation or even his involvement in the actual transgression or revolt. The remaining soldiers were then sometimes forced to make their quarters outside the main army camp and given diets of barley which were obviously harder to digest than the usual rations of wheat.

Medical Discharge –

While the life of a Roman legionary was not all about glory and triumphs as popular media would suggest, there were some progressive measures put forth by the Romans when it came to bravery. For example, if the soldier was severely injured and couldn’t continue further with his military tenure, he was given a missio causaria or medical discharge that was equivalent to honorable discharge or honesta missio. This, in turn, equated to a societal status that was higher than ordinary civilians, which made the discharged legionary exempt from taxes and other civic duties.

Now, of course, the chances of surviving after a severe injury was very low during this ancient era – even after being treated by the professional medici (surgeons and their staff) who were attached to each legion. So objectively, the missio causaria might not have been endowed on a regular basis due to ‘statistical interference’.

Beyond an Ordinary Legionary, There Were Veterans, Doctors, Engineers, and Slaves –

Roman legionary

A Roman legionary was only considered as a veteran after he had served for 16 years in the army. In the 1st century AD, even after such a long period of service, the soldier was not expected to ‘retire’ from his legion. Instead, the veteran was reinstated to a special unit of vexillum veteranorum for four more years of service.

Typically consisting of 500 to 600 men, the unit had its own administrative branch with different officers. It was however attached to the original legion, but at times were deployed independently. The latter case is evident from their separate garrison at the town of Thala, with this particular vexillum veteranorum being derived from legio III Augusta in 20 AD. Unsurprisingly, the veterans with their years of experience were highly successful against the onslaught of Tacfarinas and his Numidian forces.

Other than vexillum veteranorum, there were also slaves (or calones) that could be attached to a legion. Though unlike the veterans, they were governed as a part of the legion, with 120 men attached to each cohort of 480 soldiers. So basically, a single legion (generally comprising ten cohorts) could be accompanied by around 1,200 slaves; and these men were trained for specific tasks. During times of emergency, they were even armed with weapons to defend their camps.

And finally, the soldiers who truly made a Roman military unit self-sufficient were the immunes, a group of highly trained specialists attached to each legion. Ranging from doctors, engineers to architects, these men were exempt from the hard labor duties of the rank-and-file soldiers, while also earning more than them.

The Scutum  –

Roman legionary

The traditional shield of the Roman legionaries was the scutum. And while the standard scutum of the 1st century BC pertained to an oval-shaped shield that weighed around 10 kg (22 lbs), its shape was transformed into a curved rectangular board during the Augustan period. This change drastically reduced the weight of the shield to 7.5 kg or 16 lbs (with later specimens probably weighing even less at 5.5 kg). And as can be gathered from the transference of this weight, the shield was held by a horizontal grip with a straight arm posture.

In fact, while the rectangular scutum, roughly measuring 102 cm x 63 cm, did a good job of covering the torso of the Roman legionary, its crucial advantage lied in its offensive capacity. To that end, the legionaries slammed into their opponents with the full weight of the shield, while its prominent boss was used to violently push away and then topple the enemy. According to Tacitus (as mentioned in his Agricola), such tactics were effectively used by even the auxiliary cohorts (with their flatter shields) at Mons Graupius against the Caledonian foes.

The other incredible offensive arm was the pilum, which has been described in one of our previous posts about the Roman army.

The Roman Legionary: From Circa 2nd Century AD – 3rd Century AD

Inflated Income of Roman Legionaries –

The aforementioned service length was still ‘officially’ followed in the 3rd century AD – though some legionaries had to unconditionally serve even beyond 25 years due to the ‘Crisis of the Third Century’, a helter-skelter period during which 26 men were declared emperor by the Roman Senate in just five decades!

Emperor Septimus Severus raised the pay (by possibly 50 percent) of the Imperial Roman legionary in 197 AD, which amounted to around 450 silver denarii per quarter, or 1,800 denarii per year. This revised pay-scale came after more than a hundred years since emperor Domitian initiated some reforms in the late 1st century AD. Interestingly enough, Caracalla did one better by doubling the annual pay of the legionaries to 3,600 denarii per year – though this caused major financial strain on the treasury.

But when later emperors tried to revoke the increased pay-scale, there were numerous instances of mutinies in the Imperial Roman legionary ranks. And given the crucial nature of support (and influence) that some legions commanded, a few emperors (like Maximinus) tried to overcompensate by even doubling Caracalla’s figures in 235 AD – though such ‘appeasing’ measures were only temporary, much like the power of many 3rd century Roman emperors.

Furthermore, it should be noted that the rising inflation of the 3rd century, along with the reduced percentage of silver in the later Roman denarii, actually made the pay-hike lesser than these figures suggest. On the other hand, the Imperial legionaries were somewhat compensated by the presentation of gifts from the ascending emperor – that included gold and silver coins, along with rations. It should also be noted that many potential recruits were still drawn to the prospect of joining a legion because of the aforementioned plunder factor.

The Impracticality of ‘Full’ Fighting Legions –

Roman legionary

While Roman legions fighting with their full capacity was a regular occurrence during early 2nd century AD, by the middle of the 3rd century the conflicts faced by the Roman Empire (and the changing emperors) were pretty volatile from both the geographical and logistical scope. And so it was uncommon and rather impractical for the entire legion to leave its provincial base to fight a ‘distant’ war on the shifting frontiers of 3rd century AD.

As a solution, the Roman military commanders sanctioned the use of vexillationes – detachments from individual legions that could be easily transferred without compromising the core strength of a legion (which was needed for fortifying and policing its ‘native’ province). These mobile combat ‘divisions’, comprising one or two cohorts, were usually tasked with handling the smaller enemy forces, while also being used for garrisoning duties in strategic points like roads, bridges, and forts. And on rare occasions when the army under the Roman Empire was faced by a large number of opposing troops, many of these different vexillationes were combined to form a bigger field army.

The Founding of the Comitatus –

Comitatus from the late 3rd Century. Art by Johnny Shumate.

However, the importance of detachments was not only limited to the combat-duty bound vexillationes. Emperor Gallienus (who ruled alone from 260 to 268 AD) created his own mobile field army consisting of special detachments from the praetorians, legio II Parthica, and other guard units. Hailed as the comitatus (retinue), this central reserve force functioned under the emperor’s direct command, thus hinting at the ambit of insecurities faced by the Roman rulers and elites during the ‘Crisis of the Third Century’. Interestingly enough, many of ‘extra’ equites (cavalry) that were assigned to each conventional legion, were also inducted as the elite promoti cavalry in the already opulent (and the militarily capable) scope of the comitatus.

The Canabae Settlements of the Roman Empire –

The vexillationes system also had another major impact on the Roman Empire, this time on the social side of affairs. Since less number of soldiers had to transfer from their ‘native’ province to fight, many of the Roman legionaries started ‘settling’ around their fortresses, sometimes forming lasting relationships with the local women. As a result, settlements cropped around many legions’ barracks and military stations. Known as canabae, these ‘mini-towns’ had all the establishments tailored to the Imperial Roman legionary, including taverns, markets, and even brothels.

Interestingly enough, during the time Augustus, the legionaries were simply banned from marrying until their official discharge (though some soldiers still married in secret). This seemingly rigorous measure had a practical angle since the Romans wanted to separate their military systems from familial ties – thus decreasing the role of non-combatants (like wives and children) when entire legions were transferred elsewhere to fight their wars.

However by 197 AD, Septimus Severus revoked this law; and with the system of vexillationes further down the line, the legion became more of a static reserve of men stationed in its particular province (as opposed to a dynamic fighting force). Thus canabae settlements were more frequent in the later part of the Roman Empire, with many legionaries fulfilling the role of permanent (or semi-permanent) settlers/soldiers who lived with their wives, concubines and even families.

The Specialized ‘Elite’ Light Infantrymen –

Roman legionary
Illustration by Angus McBride

Other than smaller detachments and mobile field armies, the 3rd-century evolution of the Roman military also brought forth specialized troops who operated within the centuries-old parameters of a legion. One of these elite soldier types was known as the lanciarii. Mostly used during the Parthian Wars of Caracalla and Severus Alexander (though there are earlier mentions of them), these legionaries were possibly armed with lancea subarmales that entailed smaller throwing javelins.

Considering the types of weapons used by these troops, it can be hypothesized that the lanciarii fought as dedicated skirmishers who proceeded before the ‘heavy’ legionaries (armed with sword and conventional pila). In essence, they performed the task of flexible lightly-armed infantrymen who could deftly reorganize and counter the agile horse-archers and cavalry of the Parthians – as can be deduced from Herodian’s account of the Battle of Nisbis in 217 AD.

Now, of course, bearing the brunt of skirmishing and fighting, while also keeping up their dynamic formations in the battlefield, must have required expert levels of skill and experience on the part of the lanciarii. Such credentials allude to their elite status within the ranks of the Imperial Roman legions (especially legio II Parthica), thus harking back to the promachoi ‘champions’ of the Mycenaean Greek military during Bronze Age.

The Greek Phalanx ‘Imitators’ –

Sometimes false names can carry forth a symbolic legacy, especially when it comes to the military history of the Imperial Roman legionary. The phalangarii possibly belonged to this infamous category, with propaganda (or at least misinformed accounts) playing a big role in their ‘hype’. For example, Cassius Dio hailed the phalangarii of emperor Caracalla as a 15,000 strong army who were armed in the ‘ancient’ fashion of the Macedonian phalanx (made famous by the feats of Alexander the Great more than 500 years ago). Herodian also talks about a Spartan phalanx serving in the Roman armies. However archaeological assessments of then-contemporary gravestones of the Roman-Spartan ‘phalangites’ have shed light on how these soldiers fought in a similar manner as a conventional Imperial Roman legionary (with oval shields and swords).

So the question arises – why such ‘fake’ credentials? Well, the answer might have to do with Caracalla’s military campaign against the Parthians where the Roman emperor wanted to outvie the eminent Alexander. In fact, some of these legionaries were truly drawn from the Macedonian heartland, though most originated from Thrace. As for their pike equipment, the ancient writers may have referred to the thrusting spears that some legionaries under the Roman Empire were specially equipped with (probably to deal with enemy cavalry).

The Evolution of Longer Swords –

By 2nd century AD, the shorter sword type (gladius) of the Imperial Roman legionary was gradually substituted in favor of a longer blade weapon (possibly the spatha). Now, of course, the gladius was not completely abandoned, with its usage still prevalent among the lighter troops. And even more interestingly, in spite of their longer spans, ranging from 30 and 39-inches, the ‘newer’ swords were probably still used as thrusting weapons (rather than slashing) – thus hinting at the Roman penchant for disciplined sword fighting.

There was a practical side to this tactical scope of thrusting since the massed formations fielded by the Roman armies usually left little room for wild hacking and slashing. Moreover, the act of thrusting allowed more balance for the legionary – who could still control his shield (and torso) for better melee defense, while his ‘aggressive’ foe would have had the tendency to let his guard down to timely thrusts and cuts. The writings of Vegetius and Ammianus conform to such disciplined tactical options often demonstrated by the Imperial Roman legionary.

Tactics Against Cavalry –

Roman legionary
Illustration by Angus McBride

The Battle of Carrhae that pitted Roman consul Crassus against Parthian general Surena, outlined the shortcoming of the Roman infantry against the Parthian cavalry tactics in 1st century BC. However, by 2nd century AD, the Romans were quite successful (though at the times the overarching conflicts amounted to stalemates) against the Parthians who relied heavily on their numerous horse-archers and a few elite cataphracts. A major parcel of such favorable battle outcomes in the east had to do with the adoption of flexible infantry tactics on the part of the Romans, as opposed to full-scale employment of countering cavalry troops.

Simply put, the Romans kept up their trademark strength of massed and disciplined infantry columns, while improving their battlefield tactics with more dynamic formations and mobility. The evolution and use of lanciarii troops possibly mirrored such subtle changes to the tactical scope. Other than that there is also scant evidence of specific use of heavy cavalry divisions, like the Equites cataphractarii – though they were more common in the late Roman army rather than the Imperial Roman Army.

For example, in the Battle of Emesa (272 AD) fought between the Romans and the Palmyran forces, Emperor Aurelian opted for a standard Roman push – with his troops comprising legionaries from various parts of Europe and Asia. According to 5th-century historian Zosimus, the underwhelming Roman cavalry feigned retreat after seeing the approach of the heavy clibanarii from the Palmyran side.

Thus the pressure was on the Imperial Roman legionary detachments to secure the initiative on the battlefield – and they did so successfully by wheeling around the already scattered Palmyran forces (many of whom were still pursuing the Roman cavalry), and then routing them in a piecemeal fashion. Interestingly enough, Zosimus also mentions the devastating effect of blunt weapons like clubs and cudgels wielded by the allied Palestinian troops on the heavy cavalrymen of Palmyra.

*The article was updated on 22nd November 2019.

Book References: Roman Legionary 58 BC-AD 69 (By Ross Cowan) / Imperial Roman Legionary AD 161-284 (By Ross Cowan) / Caerleon and the Roman Army (By Richard J. Brewer) / The Roman Army from Caesar to Trajan (By Michael Simkins)

Sources: MIT.edu / UNRV / RomanRecruit (link) / Britannica / Roman-Empire (link)

About the Author

Dattatreya Mandal
Dattatreya Mandal has a bachelor's degree in Architecture (and associated History of Architecture) and a fervent interest in History. Formerly, one of the co-owners of an online architectural digest, he is currently the founder/editor of Realmofhistory.com. The latter is envisaged as an online compendium that mirrors his enthusiasm for ancient history, military, mythology, and historical evolution of architecture.