Unit 20: The Roman Army
Contents and layout ©1999 Joseph J. Hughes, Ph.D.
Revised 09 November 2000
Marius Trajan
legion Persians
auxiliaries Goths
Praetorian Guard limes
I. The army in the Republic
A. ideal of the citizen soldier
1. citizenship determined by ability to serve in army
a. outmoded in today's society
b. understandable in threatened society like Rome
c. gradations due to wealth
1). poorest: infantry
2). wealthiest: cavalry
2. no need for a professional army
a. citizens had a personal stake in the state
b. professional standing army considered subversive
1). too loyal to its commanders
2). fear was justified
B. equipment, organization
1. equipment
a. weapons
1). -hasta- (thrusting spear): first major weapon
2). -pilum- (throwing spear): replaced -hasta-
3). -gladius- (Spanish thrusting sword)
b. armor
1). -galea- (helmet)
2). -scutum- (oval shield)
c. other specialized variants
2. organization
a. legions: Roman citizens
1). 4,200-6,000 strong
2). subdivisions
a). phalanxes: original
b). 30 maniples of 120-200 men each
c). 10 cohorts of 6 centuries each (2nd cent BC)
3). battle formation
a). 3 lines of hastati, principes, triarii
b). youngest and poorest: velites
b. cavalry
1). basically rapid motion infantry; fought dismounted
2). stirrup not invented until late
c. conditions of service
1). provide your own equipment, no pay
2). commander might allow you a share of the booty
d. socii: Roman allies
1). commanded by their own leaders, but under Roman general command
2). often used as cannon fodder
C. chain of command
1. centurio : head of a century; 6 centuriones to a cohort
a. usually promoted from ranks
b. pay usually improved (5x praetorian pay in Augustan times)
2. primus pilus : centurion of first century of first cohort
a. possible promotion to praefectus castrorum
b. usually the top of the heap
3. supreme command of legion
a. Republican times: magistrate or ex-magistrate
1). not necessarily with military experience (usually some )
2). more experienced legati may have served as advisors
b. Imperial times: legatus legionis
1). selected by Augustus from ex-praetors
2). sometimes combined with governorship of province
D. the warlord phenomenon
1. citizen army no longer viable
a. Roman manpower eaten up by war
b. small farmer class being eaten up by -latifundia-
2. Marius recruits first professional army
a. pays urban poor to enlist
b. sets bad precedent
3. warlord phenomenon results
a. soldiers loyal to an individual
b. commander follows personal interests
II. The army in the High Empire
A. Augustus' reorganization of the army (280,000-300,000 men)
1. 28 -legiones-
a. professional standing army of citizens
b. loyal to Augustus alone
c. service and benefits
1). term: 20 years
2). pay: 225 denarii/year
3). land or bonus upon retirement
2. auxiliaries
a. loyal to Augustus alone
b. service and benefits
1). term: 25 years
2). pay: 75 denarii/year
3). citizenship upon retirement
3. Praetorian Guard (Italian citizens only)
a. 9,000 man bodyguard of Augustus
b. pay and benefits
1). term: 16 years
2). pay: 2 denarii/day
3). huge monetary bonus on retirement
c. develops into a force in Roman politics
1). Praetorian prefect a very powerful figure
2). eventually makes and breaks emperors
4. advantages and disadvantages of service
a. 50 % died in service
b. provided employment for poor and downtrodden
1). urban poor from Hellenistic East
3). much later, German "barbarians"
c. provided social advancement for the ambitious
1). citizenship
2). land, money, or both
3). respected figure in community
B. foreign policy during High Empire
1. conduct and objectives
a. quite aggressive during Republic
1). Rome faced with dangerous enemies
2). commanders go off on glory hunts with mixed results
a). Caesar conquers Gaul 59-51 BC
b). Crassus defeated by Parthians at Carrhae 53 BC
b. Augustus' new objectives
1). economic benefits
a). maintain contact with markets
b). exploit rich neighbors
2). security for the Empire
c. generally but not always maintained by successors
2. fight for security on the borders
a. Western Europe: Germans
1). Elbe secured by 9 BC
2). revolt of Arminius (Herman the German)
a). three legions destroyed
b). Romans retreat to Rhine
b. Central Europe/Balkans
1). Danube secured by 9 BC
2). part Roman province, part client states
c. Asia Minor
1). Rome secures Armenia 20 BC
2). tenuous peace with Parthian empire
C. Foreign policy under the Good Emperors
1. expansion in England (end of 1st c. BC)
a. first invaded by Julius Caesar (55-54 BC)
b. foothold established in 43 by Claudius
c. frontier established in Scotland 84
d. became Roman province
2. more problems on the borders
a. Jewish revolts 66-70 and 131-134
b. big nasty war on Rhine borders 167-180
c. Dacia (across the Danube) always a problem
3. Trajan's conquest of Armenia and Mesopotamia
a. previous relations with Armenia
1). Roman protectorate 20 BC
2). Nero establishes it as buffer state 64 AD
b. Trajan captures Armenia and most of Parthian territory
1). too much trouble to administer
a). too remote
b). rising Persian Empire
2). Hadrian abandons it all
4. modern-day Rumania annexed as Dacia 107
a. Danube: natural line of protection
b. abandoned by Aurelian 271 AD
III. The Army in the Third Century
A. Political role of military
1. Praetorian Guard
a. designed as bodyguard of Emperor at Rome
1). Praetorian Prefect: commander
2). often second man in Empire
b. often made emperors
1). Claudius
2). Didius Julianus
c. often broke emperors
1). Tiberius
2). Didius Julianus
2. Armies as sources of supreme power
a. happened in Republic
1). Marius vs. Sulla
2). Caesar vs. Pompey
3). Antony vs. Octavian
b. happened in High Empire
1). 68-69 AD: Year of Four Emperors
2). 213 AD: Severus et al.
c. happened all throughout the Crisis
1). declare their commanders -imperator-
2). duke it out with rival armies
3. Emperors and the military
a. compliance of army all-important
1). can make you
2). can break you
b. more of budget devoted to military
1). keep the soldiers happy
2). keep the border secure
B. Problems on the borders
1. problems in the East continue
a. Persians (Syria, Asia Minor) 260s AD
b. Goths (Balkans) 268-271 AD
2. reasons for Germanic expansion
a. desire for new homelands or for plunder
b. other tribes pushing them out
c. Roman military weakness
1). plague 260-270
2). frontier legions deserted in some instances
3. new system of frontier defenses: limes
a. arose gradually over a period of centuries
1). signal towers along R. Taunus in Germany under Domitian (90s AD)
2). Hadrian's Wall in Britain (122-126 AD)
3). Severus in Mauretania (ca. 210s AD)
b. could take any number of forms
1). stone walls in Britain and Rhaetia
2). palisade and ditch in Upper Germany
3). border fortressees (castra ) in back of major rivers
c. deployment of roving legions in the border fortresses
1). mixed German-Roman composition
2). not really all that trustworthy
d. border garrisons (auxiliaries) patrolled the limes proper
1). sometimes completely German
2). commanded by Romans
4. problems with new -limes- system
a. Germans were considered barbarian
1). unusual intoleration on Romans' part
2). Roman hostility was a bad career move
b. tremendously expensive
1). not enough money in Treasury to maintain it
2). heavy reliance on -annona- (tax in kind)
C. Army under the Dominate
1. larger than the army of the principate
2. paid by the Emperor
a. part in cash, part in -annona-
b. bonus of cash, land, and cattle upon retirement
3. arrangement of the army
a. frontier troops: -limitanei-
b. field army within empire: -comitatus-
c. Praetorian Guard replaced by -scholae-
4. admixture of Germans
a. no real attempt to Romanize the Germans
1). Romans considered them too barbaric
2). bad career move
b. heavily represented in army
1). border troops (-limitanei-)
2). also attained high positions in army
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