Organization of the Ancient Roman Military: Units, Structure, Divisions | Early European History And Religion

ORGANIZATION OF THE ROMAN MILITARY UNDER AUGUSTUS

Roman standards

A typical Roman soldier was in a unit with 80 men called a century strangely enough, with six centuries in cohort, and 10 cohorts in a legion, with about 30 legions in the entire Roman Empire. There were some cavalryman; most soldiers were foot soldiers — infantry. [Source: Daisy Dunn, The Telegraph, January 21, 2024]

J. A. S. Evans wrote: One of Augustus' most striking achievements was the organization of a professional military force which was efficient and economical. It was to last with little change for two centuries. The great army which had defeated Mark Antony was demobilized, and what Augustus kept was a force of 28 legions of 6,000 men each, if at full strength, made up of Roman citizens, supplemented by auxilia of about the same number, and recruited from non-citizen provincials. In 9 A.D., three legions were destroyed in a disaster in Germany when Arminius, chief of a German tribe known as the Cherusci, ambushed the Roman commander Publius Quinctilius Varus in the Teutoburg Forest, and the legions remained at 25 until the end of the emperor Tiberius' reign (37 A.D.). Under the emperor Vespasian (69–79 A.D.) there were still only 29. [Source: J. A. S. Evans, New Catholic Encyclopedia, Encyclopedia.com]

It was the 60 centurions in every legion who maintained discipline. The centurions were professional officers who rose through the ranks, and they might rise as high as centurion of the first rank (primipilus), but no higher. The higher officers belonged to the senatorial order. Legionary soldiers served for 20 years and received 225 denarii a year, from which rations and equipment were deducted. Until Septimius Severus (193–211), legal marriage was disallowed until discharge, when they received land grants in colonies in Italy or in the provinces. This was the general practice until 6 A.D., when Augustus established a bonus fund for the soldiers (aerarium militare) financed by an initial grant of 170 million from his personal fortune, and the revenue from a one percent sales tax (centesima venalium) and a five percent inheritance tax (vicesima hereditatium).

Thereafter a veteran generally received a cash gratuity on discharge, set at 3,000 denarii, though veterans' colonies were still occasionally founded. Auxiliary troops were commanded by Roman citizens of the equestrian order; they served 25 years and were given Roman citizenship when they were discharged. A diploma (a certificate inscribed on bronze, of which a number have been found) was given to an auxiliary on discharge. It conferred citizenship on him, his children and descendants, and the wife he had at the time of discharge, or whom he might marry later, if he were single. Presumably auxiliaries also received a bonus but at a much more modest level than the legionaries received. The Romans relied on the auxiliaries for their cavalry and light infantry, and they provided specialties that the Roman arsenal lacked, such as archers, especially mounted archers.

In Italy, the only regular army corps was the Praetorian Guard of nine cohorts, each of 1,000 troops. It was an elite force commanded by two praetorian prefects and received special treatment: guardsmen served for only 16 years, their pay scale was triple that of the legionaries, and when they retired they received more generous gratuities. Augustus never allowed more than three praetorian cohorts to remain in Rome at one time, and even they lacked a permanent camp; the remainder he quartered in neighboring towns. It was Tiberius who established the Praetorian Camp (Castra Praetoria) on the Via Tiburtina, within a built-up part of the city, though outside the pomoerium, and thereafter the praetorian prefects came to exercise ominous authority in the imperial government.

Roman Military Divisions: Cavalry, Infantry, Marine

Flavius Vegetius Renatus (died A.D. 450) wrote in “De Re Militari” (“Military Institutions of the Romans”): “The military establishment consists of three parts, the cavalry, infantry and marine. The wings of cavalry were so called from their similitude to wings in their extension on both sides of the main body for its protection. They are now called vexillations from the kind of standards peculiar to them. The legionary horse are bodies particularly annexed to each legion, and of a different kind; and on their model were organized the cavalry called Ocreati, from the light boots they wear. [Source: De Re Militari (Military Institutions of the Romans) by Flavius Vegetius Renatus (died A.D. 450), written around A.D. 390. translated from the Latin by Lieutenant John Clarke Text British translation published in 1767. Etext version by Mads Brevik (2001)]

The fleet consists of two divisions, the one of men of war called Liburnae, and the other of armed sloops. The cavalry are designed for plains. Fleets are employed for the protection of seas and rivers. The infantry are proper for the defense of eminences, for the garrisons of cities and are equally serviceable in plain and in uneven ground. The latter, therefore, from their facility of acting everywhere, are certainly the most useful and necessary troops to a state exclusively of the consideration of their being maintained at a less expense.

The infantry are divided into two corps, the legions and auxiliaries, the latter of which are furnished by allies or confederates. The peculiar strength of the Romans always consisted in the excellent organization of their legions. They were so denominated ab eligendo, from the care and exactness used in the choice of the soldiers. The number of legionary troops in an army is generally much more considerable than that of the auxiliaries.

Polybius on the Organization of the Roman Military

The historian Oliver J. Thatcher wrote: “Rome, with the end of the third Punic war, 146 B. C., had completely conquered the last of the civilized world. The best authority for this period of her history is Polybius. He was born in Arcadia, in 204 B. C., and died in 122 B.C. Polybius was an officer of the Achaean League, which sought by federating the Peloponnesus to make it strong enough to keep its independence against the Romans, but Rome was already too strong to be resisted, and arresting a thousand of the most influential members, sent them to Italy to await trial for conspiracy. Polybius had the good fortune, during seventeen years exile, to be allowed to live with the Scipios. He was present at the destructions of Carthage and Corinth, in 146 B. C., and did more than anyone else to get the Greeks to accept the inevitable Roman rule. Polybius is the most reliable, but not the most brilliant, of ancient historians.”

Polybius wrote in “History” Book 6: “From each of these several sorts of soldiers, the youngest alone excepted, ten men of distinguished merit are first selected; and after these, ten more. These are all called commanders of companies; and he that is first chosen has a seat in the military council. After these, twenty more are appointed to conduct the rear; and are chosen by the former twenty. The soldiers of each different order, the light troops excepted, are then divided into ten separate parts; to each of which are assigned four officers, of those who have been thus selected: two to lead the van, and two to take the care of the rear. The light-armed troops are distributed in just proportion among them all. Each separate part is called a company, a band, or an ensign; and the leaders, captains of companies or centurions. Last of all, two of the bravest and most vigorous among the soldiers are appointed by the captains to carry the standards of the company. [Source: Polybius (c.200-after 118 B.C.), Rome at the End of the Punic Wars, “History” Book 6. From: Oliver J. Thatcher, ed., “The Library of Original Sources” (Milwaukee: University Research Extension Co., 1907), Vol. III: The Roman World, pp. 166-193]

“It is not without good reason that two captains are assigned to every company. For as it always is uncertain, what will be the conduct of an officer, or to what accidents he may be exposed; and, as in the affairs of war, there is no room for pretext or excuse; this method is contrived, that the company may not upon any occasion be destitute of a leader. When the captains therefore both are present, he that was first chosen leads the right, and the other the left of the company. And when either of them is absent, he that remains takes the conduct of the whole. In the choice of these captains not those that are the boldest and most enterprising are esteemed the best; but those rather, who are steady and sedate; prudent in conduct, and skillful in command. Nor is it so much required, that they should be at all times eager to begin the combat, and throw themselves precipitately into action; as that, when they are pressed, or even conquered by a superior force, they should still maintain their ground, and rather die than desert their station.”

Roman Military Headquarters Found in a Serbian Cornfield

Archaeologists are excavating the well-preserved remains of a Roman legion's headquarters buried under a Serbian cornfield close to a coalmine in Kostolac, Serbia. Covering an estimated 3,500 square meters, the headquarters — or principium — belonged to the VII Claudia Legion. “There are over 100 recorded principiums across the territory of the Roman empire, but almost all are buried under modern cities, said Miomir Korac, lead archaeologist of digs there and at the Roman provincial capital Viminacium that the compound served. “A very small number of principiums are explored completely (and) ... so we can say (preservation of) this one is unique as it is undisturbed." [Source: Reuters, November 26, 2020]

Reuters reported: “The compound, which lies east of Belgrade and around one meter (3 ft) under the surface, had 40 rooms with heated walls, a treasury, a shrine, parade grounds and a fountain. Inside one room, archaeologists found 120 silver coins that "must have been lost during an emergency" such as an invasion or a natural disaster, said the principium's lead archaeologist Nemanja Mrdjic. “The distribution of coins from a corner to the door, ... suggests they (coins) spilled while someone was fleeing."

“The VII Claudia Legion was active between 2nd and 5th centuries AD, and its walled camp and principium were separated from the rest of Viminacium, which had its own fortifications. Excavations of Viminacium have been ongoing since 1882, and finds there include a Roman ship, golden tiles, jade sculptures, mosaics and frescos, along with 14,000 tombs and the remains of three mammoths. Archaeologists estimate that they have only uncovered 4% of the site, which they say its bigger than New York’s Central Park.

Roman military command structure in the late Roman Empire

Notitia Dignitatum (Register of Dignitaries), A.D. 400

The Notitia Dignitatum (Register of Dignitaries, c. A.D. 400) is an official listing of all civil and military posts in the Roman Empire, East and West. It survives as a 1551 copy of the now-missing original and is the major source of information on the administrative organization of the late Roman Empire. William Fairley wrote: “The Notitia Dignitatum is an official register of all the offices, other than municipal, which existed in the Roman Empire.... Gibbon gave to this document a date between 395 and 407 when the Vandals disturbed the Roman regime in Gaul. [Source: William Fairley, Notitia Dignitatum or Register of Dignitaries, in Translations and Reprints from Original Sources of European History, Vol. VI:4 (Philadelphia: University of Pennsylvania Press), 1899].

“The Notitia Dignitatum has preserved for us, as no other document has done, a complete outline view of the Roman administrative system in early fifth century. The hierarchic arrangement is displayed perfectly. The division of prefectures, dioceses and provinces, and the rank of their respective governors is set forth at length. The military origin of the whole system appears in the titles of the staff officers, even in those departments whose heads had, since the time of Constantine, been deprived of all military command.” The parts related to the Roman military are excerpted here:

Prefect Op the City of Constantinople

Master of the Soldiery in the Presence.
Under the control of the illustrious master of the soldiery in the, presence:
Five squadrons of palatine horse:
The senior promoted horse,
The companion cuirassiers,
The junior companion archers,
The companion Taifalians,
The Arcadian horse.
Seven squadrons of horse of the line:
The Biturigensian cuirassiers,
The senior Gallican heavy-armed horse,
The fifth Dalmatian horse,
The ninth Dalmatian horse,
The first shield-bearers,
The junior promoted horse,
The first Parthian cuirassiers.
[Source: Notitia Dignitatum (Register of Dignitaries), William Fairley, in Translations and Reprints from Original Sources of European History, Vol. VI:4 (Philadelphia: University of Pennsylvania Press), 1899].

Six palatine legions:
The senior lancers,
The junior Jovians,
The junior Herculians, The Fortenses,
The Nervii,
The junior Matiarii.
Eighteen palatine auxilia
The senior Batavians,
The junior Brachiati,
The Salians,
The Constantians,
The senior Mattiaci,
The senior Gallican archers,
The junior Gallican archers,
The third Valens' archers,
The Defenders,
The Ractobarii,
The Anglevarii,
The Hiberi,
The Visi,
The fortunate junior Honorians,
The Victors,
The first Theodosians,
The third Theodosians,
The fortunate Isaurian Theodosians.

The staff of the aforesaid office of the master in the presence is [made up from officers] enrolled with the forces and assigned to staff duty. It includes the officers below mentioned:
A chief of staff,
Two accountants (numerarii),
A custodian,
Chief clerks (primiscrinios), who become accountants,
Clerks,
Secretaries and other attendants (apparitores).
The master of the soldiery in the presence is entitled to fifteen post-warrants in the year.

Organization.
The borderers (limitanei, ripenses) were stationed on the frontiers and served as cultivators of lands allotted to them as well as soldiers.
Borderers:
Infantry
legions old, 6,ooo men, new 1000.
auxilia 500 men
Cohorts 500 men
Cavalry
Cavalry: squadrons (cunei equitum, equiles, alae); 50 men.

Imperial troops. a. Troops of the line (comitatenses)
Infantry, legions; 1,000 men.
Cavalry, squadrons (vexillationes) 1500 men.
b. Troops of the second line (pseudo-comitatenses).
c. Palatine troops, of higher rank and pay than the line.
d. The 12 schools, of 500 men each, palace guards.
B. Strength.
Total
Borderers
Infantry 249,500
360,000
Cavalry 110,500
Imperial
Infantry 145,000
194,500
Cavalry 46,500

Master of the Soldiery in the East

Under the control of the illustrious master of the soldiery in the East:
Ten squadrons of horse of the line.
Two palatine auxilia.
Nine legions of the line.
Eleven legions of the secondary line.
[Source: Notitia Dignitatum (Register of Dignitaries), William Fairley, in Translations and Reprints from Original Sources of European History, Vol. VI:4 (Philadelphia: University of Pennsylvania Press), 1899].

The staff of the master's office in the East is considered permanent.
It includes the officers below mentioned:
A chief of staff,
Two accountants,
A custodian,
A chief assistant,
Clerks,
Quartermasters (mensores),
Secretaries and other attendants.
The master of the soldiery in the East is entitled to twenty-five post-warrants in the year.

Provost of the Sacred Bedchamber.
Under the control of the illustrious provost of the sacred bedchamber:
The imperial estate (domus divina) in Cappadocia.

Master of the Offices. Under the control of the illustrious master of the offices:
The first school 1 of shield-bearers,
(1 So called from their attending in the schola, or hall of the palace.)
The second school of shield-bearers,
The school of senior gentiles,2
(2A word of no religious import, but pointing only to the origin of this school from one social class of certain Scythian peoples who were living in a federate relation to the empire.)
The school of shield- and bow-bearers,
The school of mailed shield-bearers,
The junior light-armed school,
The school of junior gentiles,
The school of confidential agents (agentes in rebus 3 and those assigned from the same school,
(3 Agentes in rebus, a class of highly paid civil agents, who were designed to keep the central government in touch with its various branches. From them were chosen, as will frequently appear, the higher staff officials, who not only served their superiors, but watched them in the interests of the court. There were 1,174 of them in the time of Theodosius II.

The surveyors and lamp-makers,
The bureau of memorials,
The bureau of correspondence,
The bureau of requests,
The bureau of assignments (dispositiones),
The staff of ushers,
The arsenals below mentioned:
of [the diocese of] the East five:
of shields and weapons, at Damascus,
of shields and weapons, at Antioch,
of mail, at Antioch,
of shields and equipment, at Edesa,
of spears, at Irenopolis in Cilicia.
of [the diocese of] Pontus three:
of cuirasses, at Caesaraea in Cappadocia,
of shields and weapons, at Nicomedia,
of cuirasses, at Nicomedia.
of [the diocese of] Asia one:
of shields and weapons, at Sardis in Lydia.
of [the diocese of] the two Thraces (one of the diocese of Asia):
of shields and weapons, at Hadrianopolis of Haemimontus
of shields and weapons, at Marcianopolis (in the two Thraces).
of [the diocese of] Illyricum four:
at Thessalonica,
at Naissus,
at Ratiaria,
of shields at Horreomargi.

The staff of the aforesaid illustrious master of the offices is made up from the school of confidential agents as follows:
A chief assistant,
Assistants:
two aids,
three for the arsenals,
four for the embroiderers in gold:
for the diocese of the East one, for the diocese of Asia one, for the diocese of Pontus one, for the diocese of the Thraces and Illyricum one.
An inspector of the public post in the presence,
Inspectors for all the provinces,
Interpreters for various peoples.
The master of the offices himself issues post-warrants.

Quaestor.
Under the control of the illustrious quaestor:
The formulation of laws,
The formulation of petitions.
The quaestor does not have a staff, but such assistants from the bureaus as he may wish.

Masters of the Foot and Horse in the Presence

Master of Foot in the Presence
Under the control of the illustrious master of foot in the presence:
The counts of the frontiers mentioned below: Italy; Africa; Tingitania; Tractus Argentoratensis; the Britains; the Saxon shore toward the Britains.
The ten dukes of the frontiers mentioned below: Mauretania Caesariensis; Tripolitanus; Pannonia secunda; ripuarian Valeria; Pannonia prima and ripuarian Noricum; Raetia prima and secunda; Belgica, secunda; Germania prima; the Britains; Mogontiacensis.
[Twelve Palatine legions *enumeration omitted
Sixty-five Palatine auxilia,
Thirty-two legions of the line,
Eighteen legions of the secondary line.]
[Source: Notitia Dignitatum (Register of Dignitaries), William Fairley, in Translations and Reprints from Original Sources of European History, Vol. VI:4 (Philadelphia: University of Pennsylvania Press), 1899].

The staff of the aforesaid master of foot in the presence:
A chief of staff,
An accountant,
A custodian,
A chief assistant,
A registrar,
Secretaries and other attendants.

Master of Horse in the Presence
Under the control of the illustrious count and master of horse in the presence:
(Ten Palatine Squadrons, Thirty-two squadrons of the line)
The staff of the aforesaid master's office.
A chief of staff,
An accountant,
A chief clerk,
A custodian,
A chief assistant,
A registrar,
Secretaries and other attendants.

Distribution of the Forces among the Various Provinces

In Italy.
[Seven palatine legions,
Twenty palatine auxilia,
Five legions of the line,
Two legions of the secondary line,
Two unclassified bodies.]
In Illyricum with the worshipful count of Illyricum:
[Thirteen palatine auxilia,
Five legions of the line,
Three legions of the secondary line,
One unclassified body.]
In the Gauls with the illustrious master of horse in Gauls:
[Fifteen palatine auxilia,
One palatine legion,
Ten legions of the line,
Ten legions of the secondary line,
Twelve unclassified bodies.]
[Source: Notitia Dignitatum (Register of Dignitaries), William Fairley, in Translations and Reprints from Original Sources of European History, Vol. VI:4 (Philadelphia: University of Pennsylvania Press), 1899].

The staff of the illustrious master of horse in the Gauls:
A chief from the staffs of the masters of soldiery in the presence, in one year from that of the master of foot, in the next from that of the master of horse.
A custodian,
Accountants from the two staffs in alternate years,
A chief assistant,
A registrar,

Secretaries and other attendants.
In the Spains with the worshipful count: [Eleven palatine auxilia, Five legions of the line.]
In Tingitania with the worshipful count: [Two palatine auxilia, Two legions of the line.]
In Africa with the worshipful count of Africa: [Three palatine legions, One palatine auxilium, Seven legions of the line.]
In the Britains with the worshipful count of the Britains: [One palatine auxilium One legion of the line, One unclassified body.]

Also squadrons of cavalry:
In Italy: [Six palatine, One of the line.]
In the Gauls with the illustrious count and master of horse in the Gauls:[Four palatine, Eight of the line.]
In Africa with the worshipful count of Africa: [Nineteen of the line.]
In Britain with the worshipful count of the Britains. [Three of the line. Two unclassified.]
In Tingitania with the worshipful count of Tingitania: [Three of the line.]

Provost of the Sacred Bedchamber
[The text relating to the provost of the sacred bedchamber is wanting.]

Insignia of the Illustrious Master of the Offices
Under the control of the illustrious master of the offices:
The first school of shield-bearers,
The second school of shield-bearers,
The senior light-armed school,
The school of senior gentiles,
The third school of shield-bearers,
The school of confidential agents and those assigned that school,
The bureau of memorials,
The bureau of assignments,
The bureau of correspondence,
The bureau of requests,
The doorkeepers,
The court ushers (cancellari).

The arsenals mentioned below:
In Illyricum;
of shields, saddle-cloths and weapons, at Sirmium,
of shields, at Acincuin,
of shields, at Carnuntum,
of shields, at Lauriacum,
of weapons, at Salona.
In Italy:
of arrows, at Concordia,
of shields and weapons, at Verona,
of leather corselets, at Mantua,
of shields, at Cremona,
of bows, at Ticinum,
of broadswords, at Luca.
In the Gauls:
of all weapons, at Argenton,
of arrows, at Macon,
of leather corselets, ballistae, and mail, at Autun,
of shields, at Autun,
of ___, at Soissons,
of broadswords, at Rheims.
of shields, at Trier,
of ballistae, at Trier,
of broadswords and shields, at Amiens.

The staff of the aforesaid illustrious master of the offices is constituted from the school of confidential agents in this manner:
A chief assistant,
A deputy of the chief assistant,
Assistants for the various arsenals,
An inspector of the public post in the presence,
Inspectors for all the provinces,
Interpreters for all peoples.

Quaestor
Under the control of the illustrious quaestor:
The formulation of laws,
The formulation of petitions.
He has subordinate clerical assistants from the various bureaus.

Image Sources: Wikimedia Commons

Text Sources: Internet Ancient History Sourcebook: Rome sourcebooks.fordham.edu ; Internet Ancient History Sourcebook: Late Antiquity sourcebooks.fordham.edu ; “Outlines of Roman History” by William C. Morey, Ph.D., D.C.L. New York, American Book Company (1901) ; “The Private Life of the Romans” by Harold Whetstone Johnston, Revised by Mary Johnston, Scott, Foresman and Company (1903, 1932); BBC Ancient Rome bbc.co.uk/history/ ; Project Gutenberg gutenberg.org ; Metropolitan Museum of Art, National Geographic, Smithsonian magazine, New York Times, Washington Post, Los Angeles Times, Live Science, Discover magazine, Archaeology magazine, Reuters, Associated Press, The Guardian, AFP, The New Yorker, Wikipedia, Encyclopædia Britannica, Encyclopedia.com and various other books, websites and publications.

Last updated November 2024