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Augustus' Military Achievements

Herbert W. Benario

Emory University

When the struggle against Antony and Cleopatra ended, Octavian found himself commander of some 60-70 legions and 900 warships. The Roman state could not, as a matter of course, support such a military establishment, nor was it politic to have so many men in service. He therefore discharged the majority, reducing the number of legions to 26; with the annexation of Galatia in 25 B.C., two new legions were added. The loss of three under Varus (see below) left only 25. There were thus about 150,000 legionaries, with an equivalent number of auxiliaries. The navy had two main bases, Misenum on the Bay of Naples and Ravenna along the Adriatic coast, with smaller flotillas elsewhere, such as at Forum Julii in southern France.

Attendant upon the emperor were the nine cohorts of the Praetorian Guard.In the later years of Augustus' principate, seven cohorts of vigiles, who served as police in Rome, were established. There were also three cohortes urbanae.  In the Res Gestae, his final statement of his activities and expenditures for the Roman state, Augustus spoke frequently of his military achievements. The text was inscribed on two bronze tablets placed in front of his mausoleum, in the Campus Martius in Rome. There survive copies from three places in Galatia, both in the Latin original and a Greek paraphrase on the walls of the pronaos of the temple of Rome and Augustus in Ankara, the Latin text from Antioch, the Greek from Apollonia in Pisidia. The military passages follow.

"4 I celebrated two ovations and three curule triumphs and I was twenty-one times saluted as imperator. The senate decreed still more triumphs to me, all of which I declined. I laid the bay leaves with which my fasces were wreathed in the Capitol after fulfilling all the vows which I had made in each war. On fifty-five occasions the senate decreed that thanksgivings should be offered to the immortal gods on account of the successes on land and sea gained by me and by my legates acting under my auspices. The days on which thanksgivings were offered in accordance with decrees of the senate numbered eight hundred and ninety. In my triumphs nine kings or children of kings were led before my chariot.

13 It was the will of our ancestors that the gateway of Janus Quirinus should be shut when victories had secured peace by land and sea and throughout the whole empire of the Roman people; from the foundation of the city down to my birth, tradition records that it was shut only twice, but while I was the leading citizen the senate resolved that it should be shut on three occasions.

26 I extended the territory of all those provinces of the Roman people on whose borders lay peoples not subject to our government. I brought peace to the Gallic and Spanish provinces as well as to Germany, throughout the area bordering on the Ocean from Cadiz to the mouth of the Elbe. I secured the pacification of the Alps from the district nearest the Adriatic to the Tuscan sea, yet without waging an unjust war on any people. My fleet sailed through the Ocean eastwards from the mouth of the Rhine to the territory of the Cimbri, a country which no Roman had visited before either by land or sea, and the Cimbri, Charydes, Semnones and other German peoples of that region sent ambassadors and sought my friendship and that of the Roman people. At my command and under my auspices two armies were led almost at the same time into Ethiopia and Arabia Felix; vast enemy forces of both peoples were cut down in battle and many towns captured. Ethiopia was penetrated as far as the town of Nabata, which adjoins Meroë: in Arabia the army advanced into the territory of the Sabaeans to the town of Mariba.

27 I added Egypt to the empire of the Roman people. Greater Armenia I might have made a province after its king, Artaxes, had been killed, but I preferred, following the model set by our ancestors, to hand over that kingdom to Tigranes, son of Artavasdes and grandson of king Tigranes; Tiberius Nero, who was then my stepson, carried this out. When the same people later rebelled and went to war, I subdued them through the agency of my son Gaius and handed them over to be ruled by King Ariobarzanes, son of Artabazus King of the Medes, and after his death to his son Artavasdes. When he was killed, I sent Tigranes, a scion of the royal Armenian house, to that kingdom. I recovered all the provinces beyond the Adriatic Sea towards the east, together with Cyrene, the greater part of them being then occupied by kings. I had previously recovered Sicily and Sardinia which had been seized in the slave war.

28 I founded colonies of soldiers in Africa, Sicily, Macedonia, both Spanish provinces, Achaea, Asia, Syria, Gallia Narbonensis and Pisidia. Italy too has twenty-eight colonies founded by my authority, which were densely populated in my lifetime.

29 By victories over enemies I recovered in Spain and Gaul, and from the Dalmatians several standards lost by other commanders. I compelled the Parthians to restore to me the spoils and standards of three Roman armies and to ask as suppliants for the friendship of the Roman people. These standards I deposited in the innermost shrine of the temple of Mars the Avenger.

30 The Pannonian peoples, whom the army of the Roman people never approached before I was the leading citizen, were conquered through the agency of Tiberius Nero, who was then my stepson and legate; I brought them into the empire of the Roman people, and extended the frontier of Illyricum to the banks of the Danube. When an army of Dacians crossed the Danube, it was defeated and routed under my auspices, and later my army crossed the Danube and compelled the Dacian peoples to submit to the commands of the Roman people. "

(tr. Brunt and Moore)

The crucial section for understanding his "constitutional" position is 34. His military capabilities rested upon his unique status, at least partially indicated here.

"34 In my sixth and seventh consulships (28-27 B.C.), after I had extinguished civil wars, and at a time when with universal consent I was in complete control of affairs, I transferred the republic from my power to the dominion of the senate and people of Rome….After this time I excelled all in influence (auctoritas), although I possessed no more official power (potestas) than others who were my colleagues in the several magistracies. "

(tr. Brunt and Moore)

Augustus names in the Res Gestae the provinces which he added to the empire. The list is very extensive, yet, since direct comparison with the achievements of any earlier imperator is omitted, the reader may not have realized that he brought more territory within the dominion of the Roman state than any other: Egypt, northern Spain, the Alpine lands, Raetia, Noricum, Pannonia, Moesia, Galatia, Paphlagonia, and part of Pontus. He thereby freed Italy from incursions by the Alpine tribes and extended the northern frontier of the empire to the Danube. His military conquests lacked the spectacular elements of those of Pompey the Great and Julius Caesar, who, respectively, settled the affairs of the East in the late sixties and conquered Gaul in the fifties. The accession of Egypt alone would have excited the spirit of the Roman people in similar fashion, yet that rich land fell into Augustus' hands essentially by default rather than as a result of major victories on the battlefield. Only in Spain and Illyricum did Augustus participate in sustained military operations.

Nor does Augustus clearly indicate where his expansionist policy met obstacles. The campaigns in Arabia and Ethiopia were both checked. The Parthians, who had defeated Roman armies and captured standards in 53, 40, and 36 B.C., were not attacked but were persuaded to return the standards of Crassus (53) in 20 B.C. This event was immortalized on the cuirass of the statue of Augustus from Prima Porta and commemorated by a triple arch to Augustus in the Roman forum which replaced a simpler, smaller one of a decade earlier. This rapprochement with the Parthians represented his most substantial diplomatic achievement, secured Rome's eastern frontiers, and spared her the enormous expense of a major war at a great distance from the Mediterranean center.

There was great public outcry for the conquest of Britain (so Horace, at least, leads us to believe) but Augustus chose not to invade the island. His aggressive foreign policy was most vividly displayed in Germany, where campaigns over a span of some twenty years ultimately came to a disastrous end when Arminius, a chieftain of the tribe of the Cherusci, himself a Roman citizen and former auxiliary officer, ambushed the legate Publius Quinctilius Varus and his three legions, XVII, XVIII, and XIX, in the Teutoburg Forest in 9 A.D. and annihilated practically the entire army. Varus committed suicide on the field of battle and the three legionary numbers were never used again. An earlier setback suffered by Lollius had proven only a minor impediment; Varus' disaster ended Roman hopes of conquering free Germany as far as the river Elbe. Its impact upon Augustus is best exemplified by the aged emperor's response; for months afterwards, he would often bang his head against a door and cry out, "Varus, give me back my legions" (Quintili Vare, legiones redde [Suetonius, Augustus 23]). Arminius' victory was the most devastating that Rome had yet suffered. Even the disasters at the hands of the Samnites and of Hannibal had only delayed the ultimate Roman triumph. This was also the case with the invasions of the Cimbri and Teutons toward the end of the second century B.C. In the course of about a decade, they destroyed five consular armies, but before long Marius conquered them in separate battles. Arminius' destruction of much of the army's offensive capacity was responsible for a major change in Roman policy, and the Elbe never became Rome's northeastern frontier. Moreover, the collapse of Augustus' dream in Germany followed hard upon a bitter and desperate uprising in Dalmatia and Pannonia, which lasted three years (6-9 A.D.) and was crushed by Tiberius in extremely hard fighting.

Augustus was not himself a great commander, although in the Illyrian campaigns of 35-33 B.C. he proved to be a capable and brave soldier who fit into the tradition of the "old Roman general." He early recognized his own shortcomings and was fortunate to have friends and relatives upon whom he could call to lead the great military enterprises. Among his boyhood companions were Marcus Vipsanius Agrippa and Quintus Salvidienus Rufus. Agrippa remained his closest friend and associate, faithful to the end, as well as becoming his son-in-law. Salvidienus proved unreliable, suspected of negotiations with Antony, and was executed in 40 B.C. His place in the counsels of the young Caesar was taken by Titus Statilius Taurus, who gained two consulates and served as prefect of the city. Augustus' stepsons Tiberius and Drusus gained great renown, with much hard fighting, in Germany and Pannonia. After Drusus' death in 9 B.C., Tiberius was Rome's prime general, his greatest achievement the crushing of the Pannonian Revolt in 6-9 A.D.

Augustus' expansionist policy was accomplished by a very small army. Ultimately the Rhine and the Danube frontiers were particularly strongly garrisoned. Permanent encampments began to be built. In Germany, along the lower and middle Rhine, there were six (from north to south): Fectio (Vechten), Noviomagus (Nijmegen), Vetera, Novaesium (Neuss), Oppidum Ubiorum (Cologne), and Moguntiacum (Mainz).The prime base along the Danube was Carnuntum, in eastern Austria.

During the civil wars, soldiers had frequently served very long periods. Discharge, care of veterans, and regularizing terms of service were important matters to which Augustus gave great attention and, as he reports in the Res Gestae, these activities involved enormous expenses.

"3 The Roman citizens who took the soldiers' oath of obedience to me numbered about 500,000. I settled rather more than 300,000 of these in colonies or sent them back to their home towns after their period of service; to all these I assigned lands or gave money as rewards for their military service.

16 I paid cash to the towns for the lands that I assigned to soldiers in my fourth consulship (30 B.C.), and later in the consulship of Marcus Crassus and Gnaeus Lentulus (14 B.C.). The sum amounted to about 600,000,000 sesterces paid for lands in Italy, and about 260,000,000 disbursed for provincial lands. Of all those who founded military colonies in Italy or the provinces I was the first and only one to have done this in the recollection of my contemporaries. Later…I paid monetary rewards to soldiers whom I settled in their home towns after completion of their service, and on this account I expended about 400,000,000 sesterces."

(tr. Brunt and Moore)

When the number of legions was reduced to 26, the term of service was set at sixteen years, while auxiliaries served twenty. In 5 A.D., Augustus ceased settling veterans in colonies or any other specified places and gave each man a discharge bonus of 12,000 sesterces, a sum equivalent to twelve years' pay. Even the seemingly infinite resources of the princeps were incapable of meeting such an obligation regularly. As a result, in the following year, terms of service were lengthened (legionaries to twenty years, auxiliaries to twenty-five) to reduce the immediate requirements of bonuses and the aerarium militare (military treasury) was established. It was now the state's responsibility, rather than his own, to reward legionaries for faithful service. Augustus gave an initial gift to the aerarium militare of 170,000,000 sesterces (RG 17); thereafter it was funded by a five per cent duty on inheritances (the vicesima hereditatum) and a one per cent duty on auction sales (the centesima rerum venalium). Auxiliaries received citizenship upon discharge.


General works

Bengtson, Hermann.  Kaiser Augustus: Sein Leben und seine Zeit (München 1981)

Bleicken, Jochen.  Augustus (Berlin 1998)

Brunt, P. A. and J.M. Moore,  Res Gestae Divi Augusti. The Achievements of the Divine Augustus (Oxford 1967)

Earl, Donald.  The Age of Augustus (London 1968)

Eck, Werner.  Augustus (Oxford 2003)

Hammond,  Mason.  The Augustan Principate (New York 1968 2nd edition)

Holmes, T. Rice.  The Architect of the Roman Empire (Oxford 1928-31)

Jones,  A.H.M. Augustus (London 1970)

Kähler, Heinz. Die Augustusstatue von Primaporta (Köln 1959)

Kaiser Augustus und die verlorene Republik (Mainz 1988)

Kienast, Dietmar.  Augustus. Prinzeps und Monarch (Darmstadt 1999 3rd edition)

Syme, Ronald.  The Roman Revolution (Oxford 1939)

Paribeni, Roberto.  L'età di Cesare e di Augusto (Bologna 1950)

Shotter, David.  Augustus Caesar (London 2005 2nd edition)

Southern, Pat.  Augustus (London 1998)

The Roman army

Cheesman, G.L. The Auxilia of the Roman Imperial Army (Oxford 1914) "Introduction: The Military Reforms of Augustus"

Durry, Marcel.  Les Cohortes Prétoriennes (Paris 1938)

Grant, Michael.  The Army of the Caesars (London 1974) "Part II: The Army of Augustus"

Holder, P.A.  Studies in the Auxilia of the Roman Army from Augustus to Trajan (Oxford 1980)

Keppie, Lawrence.  The Making of the Roman Army. From Republic to Empire (London 1984)

Le Bohec, Yann.  The Imperial Roman Army (London 1994)

Saddington, D.B.  The Development of the Roman Auxiliary Forces from Caesar to Vespasian (49 B.C- A.D. 79) (Harare, Zimbabwe 1982)

Webster, Graham.  The Roman Imperial Army of the First and Second Centuries A.D. (Totowa, NJ 1985 3rd edition)

The Roman navy

Kienast, Dietmar.  Untersuchungen zu den Kriegsflotten der römischen Kaiserzeit (Bonn 1966)

Starr, Chester G. The Roman Imperial Navy 31 B.C.- A.D. 324 (Cambridge 1960 2nd edition)

The army, wars, and military policy under Augustus

Anderson, J.G.C.  "The Eastern Frontier under Augustus," Cambridge Ancient History X (1934)

Barnes, Timothy D.  "The Triumphs of Augustus," Journal of Roman Studies 64 (1974) 21-26

Benario,  Herbert W.  "Teutoburg," Classical World 96 (2002-2003) 397-408

Bordewich, Fergus M.   "The Ambush That Changes History," Smithsonian (September 2005) 74-

Carter, John M.  The Battle of Actium (London 1970)

 Gruen,  Erich S.  "The Expansion of the empire under Augustus," Cambridge Ancient History X
(1996 2nd edition) 147-197

Kalkriese - 15 Jahre Archäologie. Eine Entdeckung und ihre Folgen (Kalkriese 2005)

Raaflaub, Kurt A.  "The political significance of Augustus' military reforms," Roman Frontier
Studies 1979 (Oxford 1980) 1005-1025

Syme, Ronald.  "Some Notes on the Legions under Augustus," Journal of Roman Studies 23
(1933) 14-33

________.  "The Northern Frontiers under Augustus," Cambridge Ancient History X 340-381

Wells, Colin M.  The German Policy of Augustus (Oxford 1972)


Keppie, Lawrence.  Colonisation and Veteran Settlement in Italy, 47-14 BC (London 1983)

Levick, Barbara. Roman Colonies in Southern Asia Minor (Oxford 1967)

Copyright (C) 2008, Herbert W. Benario. This file may be copied on the condition that the entire contents, including the header and this copyright notice, remain intact.

Comments to: Herbert W. Benario

Updated:31 March 2008

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