Roman army - WikiHQ

thumb|right|upright|Coin showing (obverse) head of the late Roman emperor [[Julian the Apostate|Julian (ruled 361–363 AD) wearing diadem and (reverse) soldier bearing standard holding kneeling barbarian captive by the hair, legend and Myth ('Valour of Roman army'). Gold solidus. Sirmium mint.]]

The Roman Army () served ancient Rome and the Roman people enduring through the Roman Kingdom (753–509 BC), the Roman Republic (509–27 BC), and the Roman Empire (27 BC – AD 476/1453), including the Western Roman Empire (collapsed AD 476/480) and the Eastern Roman Empire (collapsed AD 1453). It is thus a term that broadly spans approximately 2,206 years, during which the force underwent numerous permutations in size, composition, organization, equipment and tactics, while conserving a core of lasting traditions.

Early Roman army (c. 550 – c. 300 BC)

Until , there was no "national" Roman army, but a series of clan-based war-bands which only coalesced into a united force in periods of serious external threat. Around 550 BC, during the period conventionally known as the rule of king Servius Tullius, it appears that a universal levy of eligible adult male citizens was instituted. This development apparently coincided with the introduction of heavy armour for most of the infantry. Although originally low in numbers, the Roman infantry was extremely effective and developed some influential battle strategies.

The early Roman army was based on a compulsory levy from adult male citizens which was held at the start of each campaigning season, in those years that war was declared. There were no standing or professional forces. During the regal period (to c. 500 BC), the standard levy was probably of 9,000 men, consisting of 6,000 heavily armed infantry (probably Greek-style hoplites), plus 2,400 light-armed infantry (rorarii, later called velites) and 600 light cavalry (). When the kings were replaced by two annually elected praetores in c. 500 BC, the standard levy remained of the same size, but was now divided equally between the praetors, each commanding one legion of 4,500 men.

It is likely that the hoplite element was deployed in a Greek-style phalanx formation in large set-piece battles. However, these were relatively rare, with most fighting consisting of small-scale border-raids and skirmishing. In these, the Romans would fight in their basic tactical unit, the centuria of 100 men. In addition, separate clan-based forces remained in existence until at least, although they would operate under the Praetors' authority, at least nominally.

In 493 BC, shortly after the establishment of the Roman Republic, Rome concluded a perpetual treaty of military alliance (the Foedus Cassianum), with the combined other Latin city-states. The treaty, probably motivated by the need for the Latins to deploy a united defence against incursions by neighbouring hill-tribes, provided for each party to provide an equal force for campaigns under unified command. It remained in force until 358 BC.

Roman army of the mid-Republic (c. 300 – 107 BC)

thumb|Levy of the army, detail of the carved [[relief on the Altar of Domitius Ahenobarbus, 122–115 BC.]]

The central feature of the Roman army of the mid-Republic, or the Polybian army, was the manipular organization of its battle-line. Instead of a single, large mass (the phalanx) as in the Early Roman army, the Romans now drew up in three lines consisting of small units (maniples) of 120 men, arrayed in chessboard fashion, giving much greater tactical strength and flexibility. This structure was probably introduced in c. 300 BC during the Samnite Wars. Also probably dating from this period was the regular accompaniment of each legion by a non-citizen formation of roughly equal size, the ala, recruited from Rome's Italian allies, or socii. The latter were approximately 150 autonomous states which were bound by a treaty of perpetual military alliance with Rome. Their sole obligation was to supply to the Roman army, on demand, a number of fully equipped troops up to a specified maximum each year.

The Second Punic War (218–201 BC) saw the addition of a third element to the existing dual Roman/Italian structure: non-Italian mercenaries with specialist skills lacking in the legions and alae: Numidian light cavalry, Cretan archers, and Balearic slingers. From this time, these units always accompanied Roman armies.

The Republican army of this period, like its earlier forebear, did not maintain standing or professional military forces, but levied them, by compulsory conscription, as required for each campaigning season and disbanded thereafter (although formations could be kept in being over winter during major wars). The standard levy was doubled during the Samnite Wars to four legions (two per consul), for a total of c. 18,000 Roman troops and four allied alae of similar size. Service in the legions was limited to property-owning Roman citizens, normally those known as iuniores (age 16–46). The army's senior officers, including its commanders-in-chief, the Roman consuls, were all elected annually at the People's Assembly. Only equites (members of the Roman knightly order) were eligible to serve as senior officers. of the highest social classes ( and the First Class of commoners) provided the legion's cavalry, the other classes the legionary infantry. The (those assessed at under 400 wealth) were ineligible for legionary service and were assigned to the fleets as oarsmen. Elders, vagrants, freedmen, slaves and convicts were excluded from the military levy, save in emergencies.

The legionary cavalry also changed, probably around 300 BC onwards from the light, unarmoured horse of the early army to a heavy force with metal armour (bronze cuirasses and, later, chain-mail shirts). Contrary to a long-held view, the cavalry of the mid-Republic was a highly effective force that generally prevailed against strong enemy cavalry forces (both Gallic and Greek) until it was decisively beaten by the Carthaginian general Hannibal's horsemen during the Second Punic War. This was due to Hannibal's greater operational flexibility owing to his Numidian light cavalry.

The Polybian army's operations during its existence can be divided into three broad phases. (1) The struggle for hegemony over Italy, especially against the Samnite League (338–264 BC); (2) the struggle with Carthage for hegemony in the western Mediterranean Sea (264–201 BC); and (3) the struggle against the Hellenistic monarchies for control of the eastern Mediterranean (201–91 BC). During the earlier phase, the normal size of the levy (including allies) was in the region of 40,000 men (two consular armies of c. 20,000 men each).

thumb|upright|[[Gaius Marius, to whom later historians would misattribute putative reforms of the Roman army]]

During the latter phase, with lengthy wars of conquest followed by permanent military occupation of overseas provinces, the character of the army necessarily changed from a temporary force based entirely on short-term conscription to a standing army in which the conscripts, whose service was in this period limited by law to six consecutive years, were complemented by large numbers of volunteers who were willing to serve for much longer periods. Many of the volunteers were drawn from the poorest social class, which until the Second Punic War had been excluded from service in the legions by the minimum property requirement: during that war, extreme manpower needs had forced the army to ignore the requirement, and this practice continued thereafter. Maniples were gradually phased out as the main tactical unit, and replaced by the larger cohorts used in the allied ', a process probably complete by the time the general Marius assumed command in 107 BC. (The so-called "Marian reforms" of the army hypothesised by some scholars are today seen by other scholars as having evolved earlier and more gradually.)

In the period after the defeat of Carthage in 201 BC, the army was campaigning exclusively outside Italy, resulting in its men being away from their home plots of land for many years at a stretch. They were assuaged by the large amounts of booty that they shared after victories in the rich eastern theatre. But in Italy, the ever-increasing concentration of public lands in the hands of big landowners, and the consequent displacement of the soldiers' families, led to great unrest and demands for land redistribution. This was successfully achieved, but resulted in the disaffection of Rome's Italian allies, who as non-citizens were excluded from the redistribution. This led to the mass revolt of the ' and the Social War (91-88 BC). The result was the grant of Roman citizenship to all Italians and the end of the Polybian army's dual structure: the were abolished and the recruited into the legions.

Imperial Roman army (30 BC – AD 284)

Under the founder–emperor Augustus (ruled 30 BC – 14 AD), the legions, c. 5,000-strong all-heavy infantry formations recruited from Roman citizens only, were transformed from a mixed conscript and volunteer corps serving an average of 10 years, to all-volunteer units of long-term professionals serving a standard 25-year term (conscription was only decreed in emergencies). In the later 1st century, the size of a legion's First Cohort was doubled, increasing legionary personnel to c. 5,500.

thumb|left|Roman auxiliary infantry crossing a river. They can be distinguished by the oval shield ([[clipeus) they were equipped with, in contrast to the rectangular scutum carried by legionaries. Panel from Trajan's Column, Rome]]

Alongside the legions, Augustus established the auxilia, a regular corps of similar numbers to the legions, recruited from the peregrini (non-citizen inhabitants of the empire – about 90% of the empire's population in the 1st century). As well as comprising large numbers of extra heavy infantry equipped in a similar manner to legionaries, the auxilia provided virtually all the army's cavalry (heavy and light), light infantry, archers and other specialists. The auxilia were organised in c. 500-strong units called (all-infantry), (all-cavalry) and (infantry with a cavalry contingent attached). Around 80 AD, a minority of auxiliary regiments were doubled in size. Until about 68 AD, the auxilia were recruited by a mix of conscription and voluntary enlistment. After that time, the auxilia became largely a volunteer corps, with conscription resorted to only in emergencies. Auxiliaries were required to serve a minimum of 25 years, although many served for longer periods. On completion of their minimum term, auxiliaries were awarded Roman citizenship, which carried important legal, fiscal and social advantages. Alongside the regular forces, the army of the Principate employed allied native units (called numeri) from outside the empire on a mercenary basis. These were led by their own aristocrats and equipped in traditional fashion. Numbers fluctuated according to circumstances and are largely unknown.

As all-citizen formations, and symbolic guarantors of the dominance of the Italian hegemony, legions enjoyed greater social prestige than the auxilia. This was reflected in better pay and benefits. In addition, legionaries were equipped with more expensive and protective armour than auxiliaries. However, in 212, the emperor Caracalla granted Roman citizenship to all the empire's inhabitants. At this point, the distinction between legions and auxilia became moot, the latter becoming all-citizen units also. The change was reflected in the disappearance, during the 3rd century, of legionaries' special equipment, and the progressive break-up of legions into cohort-sized units like the auxilia.

thumb|upright|Roman relief fragment depicting the [[Praetorian Guard, c. 50 AD]]

By the end of Augustus' reign, the imperial army numbered some 250,000 men, equally split between legionaries and auxiliaries (25 legions and c. 250 auxiliary regiments). The numbers grew to a peak of about 450,000 by 211 (33 legions and c. 400 auxiliary regiments). By then, auxiliaries outnumbered legionaries substantially. From the peak, numbers probably underwent a steep decline by 270 due to plague and losses during multiple major barbarian invasions. Numbers were restored to their early 2nd-century level of c. 400,000 (but probably not to their 211 peak) under Diocletian (r. 284–305). After the empire's borders became settled (on the Rhine-Danube line in Europe) by 68, virtually all military units (except the Praetorian Guard) were stationed on or near the borders, in roughly 17 of the 42 provinces of the empire in the reign of Hadrian (r. 117–138).

The military chain of command was relatively uniform across the Empire. In each province, the deployed legions' legati (legion commanders, who also controlled the auxiliary regiments attached to their legion) reported to the (provincial governor), who also headed the civil administration. The governor in turn reported directly to the emperor in Rome. There was no army general staff in Rome, but the leading praefectus praetorio (commander of the Praetorian Guard) often acted as the emperor's de facto military chief-of-staff.

Legionary rankers were relatively well-paid, compared to contemporary common labourers. Compared with their subsistence-level peasant families, they enjoyed considerable disposable income, enhanced by periodic cash bonuses on special occasions such as the accession of a new emperor. In addition, on completion of their term of service, they were given a generous discharge bonus equivalent to 13 years' salary. Auxiliaries were paid much less in the early 1st century, but by 100 AD, the differential had virtually disappeared. Similarly, in the earlier period, auxiliaries appear not to have received cash and discharge bonuses, but probably did so from Hadrian onwards. Junior officers (), the equivalent of non-commissioned officers in modern armies, could expect to earn up to twice basic pay. Legionary centurions, the equivalent of mid-level commissioned officers, were organised in an elaborate hierarchy. Usually risen from the ranks, they commanded the legion's tactical sub-units of centuriae (c. 80 men) and cohorts (c. 480 men). They were paid several multiples of basic pay. The most senior centurion, the , was elevated to equestrian rank upon completion of his single-year term of office. The senior officers of the army, the (legion commanders), tribuni militum (legion staff officers) and the praefecti (commanders of auxiliary regiments) were all of at least equestrian rank. In the 1st and early 2nd centuries, they were mainly Italian aristocrats performing the military component of their (conventional career path). Later, provincial career officers became predominant. Senior officers were paid very high salaries, multiples of at least 50 times basic.

A typical Roman army during this period consisted of five to six legions. One legion was made up of ten cohorts. The first cohort had five each of 160 soldiers. In the second through tenth cohorts there were six ' of 80 men each. These do not include archers, cavalry or officers.

thumb|left|Relief scene of Roman legionaries building a road, from [[Trajan's Column, Museum of Roman Civilization, Rome]]

Soldiers spent only a fraction of their lives on campaign. Most of their time was spent on routine military duties such as training, patrolling, and maintenance of equipment, etc. Soldiers also played an important role outside the military sphere. They performed the function of a provincial governor's police force. As a large, disciplined and skilled force of fit men, they played a crucial role in the construction of a province's Roman military and civil infrastructure: in addition to constructing forts and fortified defences such as Hadrian's Wall, they built roads, bridges, ports, public buildings, entire new cities (Roman colonies), and also engaged in large-scale forest clearance and marsh drainage to expand the province's available arable land.

Soldiers, mostly drawn from polytheistic societies, enjoyed wide freedom of worship in the polytheistic Roman system. They revered their own native deities, Roman deities and the local deities of the provinces in which they served. Only a few religions were banned by the Roman authorities, as being incompatible with the official Roman religion and/or politically subversive, notably Druidism and Christianity. The later Principate saw the rise in popularity among the military of Eastern mystery cults, generally centred on one deity, and involving secret rituals divulged only to initiates. By far the most popular in the army was Mithraism, an apparently syncretist religion which mainly originated in Asia Minor.

{| class="wikitable"

|+ Summary of key structural shifts in Roman military organization<br />

Figures represent midpoint estimates derived from ancient sources and modern scholarship; ancient figures are approximate and subject to ±25–40% uncertainty due to source limitations, rhetorical inflation, and changing institutional definitions.

! Period

! Approx. total strength

! Core unit strength

| Early Republic

| 10,000–20,000 (seasonal levy)

| 3,000–4,000

| Middle Republic

| ~50,000–100,000 (wartime mobilization)

| 4,200–5,000

| 5,000–6,000

| 5,200

| 5,200+

| Mixed mercenary, settler, and subject recruitment

| Manpower scalability

| High and institutionalized

| Limited replacement capacity

| Political integration

| Citizenship expansion Yet, through a combination of skill, determination and years of campaigning, Alexios, John and Manuel Komnenos managed to restore the power of the Byzantine Empire by constructing a new army from scratch. This process should not, however, at least in its earlier phases, be seen as a planned exercise in military restructuring. In particular, Alexios I was often reduced to reacting to events rather than controlling them; the changes he made to the Byzantine army were largely done out of immediate necessity and were pragmatic in nature.

The new force had a core of units which were both professional and disciplined. It contained formidable guards units such as the Varangians, the Athanatoi, a unit of heavy cavalry stationed in Constantinople, the Vardariotai and the Archontopouloi, recruited by Alexios from the sons of dead Byzantine officers, foreign mercenary regiments, and also units of professional soldiers recruited from the provinces. These provincial troops included kataphraktoi cavalry from Macedonia, Thessaly and Thrace, and various other provincial forces such as Trebizond archers from the Black Sea coast of Anatolia. Alongside troops raised and paid for directly by the state the Komnenian army included the armed followers of members of the wider imperial family and its extensive connections. In this can be seen the beginnings of the feudalisation of the Byzantine military. The granting of pronoia holdings, where land, or more accurately rights to revenue from land, was held in return for military obligations, was beginning to become a notable element in the military infrastructure towards the end of the Komnenian period, though it became much more important subsequently.

In 1097, the Byzantine army numbered around 70,000 men altogether. By 1180 and the death of Manuel Komnenos, whose frequent campaigns had been on a grand scale, the army was probably considerably larger. During the reign of Alexios I, the field army numbered around 20,000 men which was increased to about 30,000 men in John II's reign. By the end of Manuel I's reign the Byzantine field army had risen to 40,000 men.

Palaiologan Byzantine army (1261–1453)

The Palaiologan army refers to the military forces of the Byzantine Empire from the late 13th century to its final collapse in the mid 15th century, under the House of the Palaiologoi. The army was a direct continuation of the forces of the Nicaean army, which itself was a fractured component of the formidable Komnenian army. Under the first Palaiologan emperor, Michael VIII, the army's role took an increasingly offensive role whilst the naval forces of the Empire, weakened since the days of Andronikos I Komnenos, were boosted to include thousands of skilled sailors and some 80 ships. Due to the lack of land to support the army, the Empire required the use of large numbers of mercenaries.

After Andronikos II took to the throne, the army fell apart and the Byzantines suffered regular defeats at the hands of their eastern opponents, although they would continue to enjoy success against the crusader territories in Greece. By c. 1350, following a destructive civil war and the outbreak of the Black Death, the Empire was no longer capable of raising troops and the supplies to maintain them. The Empire came to rely upon troops provided by Serbs, Bulgarians, Venetians, Latins, Genoans and Ottoman Turks to fight the civil wars that lasted for the greater part of the 14th century, with the latter foe being the most successful in establishing a foothold in Thrace. The Ottomans swiftly expanded through the Balkans and cut off Constantinople, the capital of the Byzantine Empire, from the surrounding land. The last decisive battle was fought by the Palaiologan army in 1453, when Constantinople was besieged and fell on 29 May. The last isolated remnants of the Byzantine state were conquered by 1461.

References

Bibliography

External links

Ross Cowan, Roman Legionary 109-58 BC: The Age of Marius, Sulla and Pompey the Great
Ross Cowan, Roman Legionary AD 69-161
Ross Cowan, Roman Legionary AD 284-337: The Age of Diocletian and Constantine
Diocletian and the Roman Army
Life of Roman legionary
Roman Warriors: The Myth of the Military Machine