Campaign history of the Roman military

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From its origin as a city-state on the peninsula of

Despite their formidable reputation and host of victories, Roman armies were not invincible.[4] Romans "produced their share of incompetents"^[5] who led Roman armies into catastrophic defeats. Nevertheless, it was generally the fate of even the greatest of Rome's enemies, such as Pyrrhus and Hannibal, to win the battle but lose the war. The history of Rome's campaigning is, if nothing else, a history of obstinate persistence overcoming appalling losses.^[6][7]

Kingdom (753–509 BC)

Knowledge of Roman history stands apart from other civilizations in the ancient world. Its chronicles, military and otherwise, document

Rome's earliest history, from the time of its founding as a small tribal village,^[8] to the downfall of its kings, is the least well preserved. Although the early Romans were literate to some degree,^[9] this void may be due to the lack of will to record their history at that time, or such histories as they did record were lost.^[10]

Although the Roman historian

The first of the campaigns fought by the Romans in this legendary account are the wars with various Latin cities and the Sabines. According to Livy, the Latin village of Caenina responded to the event of the abduction of the Sabine women by invading Roman territory, but were routed and their village captured. The Latins of Antemnae and those of Crustumerium were defeated next in a similar fashion. The remaining main body of the Sabines attacked Rome and briefly captured the citadel, but were then convinced to conclude a treaty with the Romans under which the Sabines became Roman citizens.^[21]

There was a further war in the 8th century BC against

Lucius Tarquinius Priscus' first war was waged against the Latins. Tarquinius took the Latin town of Apiolae by storm and took great booty from there back to Rome.^[22] According to the Fasti Triumphales, the war occurred prior to 588 BC.

His military ability was tested by an

Tarquin next began a war against the Volsci. He took the wealthy town of Suessa Pometia, with the spoils of which he commenced the erection of the Temple of Jupiter Optimus Maximus which his father had vowed. He also celebrated a triumph for his victory.^[27]

He was next engaged in a war with Gabii, one of the Latin cities, which had rejected the Latin treaty with Rome. Unable to take the city by force of arms, Tarquin had his son, Sextus Tarquinius, infiltrate the city, gain the trust of its people and command of its army. In time he killed or exiled the city's leaders, and handed control of the city over to his father.^[28]

Tarquin also agreed to a peace with the

Tarquinius later went to war with the Rutuli. According to Livy, the Rutuli were, at that time, a very wealthy nation. Tarquinius was desirous of obtaining the booty which would come with victory over the Rutuli.^[30] Tarquin unsuccessfully sought to take the Rutulian capital, Ardea, by storm, and subsequently began an extensive siege of the city. The war was interrupted by the revolution which overthrew the Roman monarchy. The Roman army, camped outside Ardea, welcomed Lucius Junius Brutus as their new leader, and expelled the king's sons. It is unclear what was the outcome of the siege, or indeed the war.^[31]

Republic

Early (509–275 BC)

Early Italian campaigns (509–396 BC)

The first non-apocryphal Roman wars were wars of both expansion and defence, aimed at protecting Rome itself from neighbouring cities and nations and establishing its territory in the region.^[32] Florus writes that at this time "their neighbours, on every side, were continually harassing them, as they had no land of their own ... and as they were situated, as it were, at the junction of the roads to Latium and Etruria, and, at whatever gate they went out, were sure to meet a foe."^[33]

In the semi-legendary period of the early republic, sources record Rome was twice attacked by Etruscan armies. About 509 BC

After swiftly recovering from the sack of Rome,

Rome was therefore forced to contend by around 340 BC against both Samnite incursions into their territory and, simultaneously, in a bitter war against their former allies. Rome bested the Latins in the Battle of Vesuvius and again in the Battle of Trifanum,^[66] after which the Latin cities were obliged to submit to Roman rule.^[67][68] Perhaps due to Rome's lenient treatment of their defeated foe,^[65] the Latins submitted largely amicably to Roman rule for the next 200 years.

The

By the beginning of the 3rd century Rome had established itself as a major power on the

In the naval Battle of Thurii,^[74] Tarentum appealed for military aid to Pyrrhus, ruler of Epirus.^[74][75] Motivated by his diplomatic obligations to Tarentum, and a personal desire for military accomplishment,^[76] Pyrrhus landed a Greek army of some 25,000 men^[74] and a contingent of war elephants^[74][77] on Italian soil in 280 BC,^[78] where his forces were joined by some Greek colonists and a portion of the Samnites who revolted against Roman control, taking up arms against Rome for the fourth time in seventy years.

The Roman army had not yet seen elephants in battle,

When his Sicilian campaign was also ultimately a failure, and at the request of his Italian allies, Pyrrhus returned to Italy to face Rome once more. In 275 BC, Pyrrhus again met the Roman army at the Battle of Beneventum.^[80] This time the Romans had devised methods to deal with the war elephants, including the use of javelins,^[80] fire^[83] and, one source claims, simply hitting the elephants heavily on the head.^[77] While Beneventum was indecisive,^[83] Pyrrhus realised that his army had been exhausted and reduced by years of foreign campaigns, and seeing little hope for further gains, he withdrew completely from Italy.

The conflicts with Pyrrhus would have a great effect on Rome. It had shown that it was capable of pitting its armies successfully against the dominant military powers of the Mediterranean, and further showed that the Greek kingdoms were incapable of defending their colonies in Italy and abroad. Rome quickly moved into southern Italia, subjugating and dividing Magna Grecia.^[84] Effectively dominating the Italian peninsula,^[85] and with a proven international military reputation,^[86] Rome now began to look to expand from the Italian mainland. Since the Alps formed a natural barrier to the north, and Rome was none too keen to meet the fierce Gauls in battle once more, the city's gaze turned to Sicily and the islands of the Mediterranean, a policy that would bring it into direct conflict with its former ally Carthage.^[86][87]

Middle (274–148 BC)

Rome first began to make war outside the Italian peninsula during the

Punic Wars (264–146 BC)

The First Punic War began in 264 BC when settlements on Sicily began to appeal to the two powers between which they lay – Rome and Carthage – in order to solve internal conflicts.^[89] The willingness of both Rome and Carthage to become embroiled on the soil of a third party may indicate a willingness to test each other's power without wishing to enter a full war of annihilation; certainly there was considerable disagreement within Rome about whether to prosecute the war at all.^[91] The war saw land battles in Sicily early on, such as the Battle of Agrigentum, but the theatre shifted to naval battles around Sicily and Africa. For the Romans, naval warfare was a relatively unexplored concept.^[92] Before the First Punic War in 264 BC there was no Roman navy to speak of, as all previous Roman wars had been fought on land in Italy. The new war in Sicily against Carthage, a great naval power,^[93] forced Rome to quickly build a fleet and train sailors.^[94]

Rome took to naval warfare "like a brick to water"

Carthage never managed to recover after the Second Punic War[121] and the Third Punic War that followed was in reality a simple punitive mission to raze the city of Carthage to the ground.^[122] Carthage was almost defenceless and when besieged offered immediate surrender, conceding to a string of outrageous Roman demands.^[123] The Romans refused the surrender, demanding as their further terms of surrender the complete destruction of the city^[124] and, seeing little to lose,^[124] the Carthaginians prepared to fight.^[123] In the Battle of Carthage the city was stormed after a short siege and completely destroyed,^[125] its culture "almost totally extinguished".^[126]

Conquest of the Iberian peninsula (219–18 BC)

Rome's conflict with the

Since the Roman invasion of the Iberian peninsula had begun in the south in the territories around the Mediterranean controlled by the Barcids, the last region of the peninsula to be subdued lay in the far north. The Cantabrian Wars or Astur-Cantabrian Wars, from 29 BC to 19 BC, occurred during the Roman conquest of these northern provinces of Cantabria and Asturias. Iberia was fully occupied by 25 BC and the last revolt put down by 19 BC^[137]

Macedon, the Greek poleis, and Illyria (215–148 BC)

Rome's preoccupation with its war with Carthage provided an opportunity for

The First Macedonian War saw the Romans involved directly in only limited land operations. When the Aetolians sued for peace with Philip, Rome's small expeditionary force, with no more allies in Greece, was ready to make peace. Rome had achieved its objective of pre-occupying Philip and preventing him from aiding Hannibal.^[141] A treaty was drawn up between Rome and Macedon at Phoenice in 205 BC which promised Rome a small indemnity,^[125] formally ending the First Macedonian War.^[142]

Macedon began to encroach on territory claimed by several other Greek city states in 200 BC and these pleaded for help from their newfound ally Rome.

Rome now turned its attentions to Antiochus III of the Seleucid Empire to the east. After campaigns as far abroad as Bactria, India, Persia and Judea, Antiochus moved to Asia Minor and Thrace^[153] to secure several coastal towns, a move that brought him into conflict with Roman interests. A Roman force under Manius Acilius Glabrio defeated Antiochus at the Battle of Thermopylae^[147] and forced him to evacuate Greece:^[154] the Romans then pursued the Seleucids beyond Greece, beating them again in naval battles at the Battle of the Eurymedon and Battle of Myonessus, and finally in a decisive engagement of the Battle of Magnesia.^[154][155]

In 179 BC Philip died

The Fourth Macedonian War, fought from 150 BC to 148 BC, was the final war between Rome and Macedon and began when Andriscus usurped the Macedonian throne. The Romans raised a consular army under Quintus Caecilius Metellus, who swiftly defeated Andriscus at the Second battle of Pydna.

Under Lucius Mummius, Corinth was destroyed following a siege in 146 BC, leading to the surrender and thus conquest of the Achaean League (see Battle of Corinth).

Late (147–30 BC)

Jugurthine War (112–105 BC)

Rome had, in the earlier Punic Wars, gained large tracts of territory in Africa, which they consolidated in the following centuries.

Memories of the sack of Rome by Celtic tribes from Gaul in 390/387 BC, had been made into a legendary account that was taught to each generation of Roman youth, were still prominent despite their historical distance. In 121 BC, Rome came into contact with the Celtic tribes of the Allobroges and the Arverni, both of which they defeated with apparent ease in the First Battle of Avignon near the Rhone river and the Second Battle of Avignon, the same year.^[178]

New Germanic threat (113–101 BC)

The

During a term as praetor in Iberia, Pompey's contemporary

("Commentaries on the Gallic War").

Gaul never regained its Celtic identity, never attempted another nationalist rebellion, and remained loyal to Rome until the fall of the Western Empire in 476 AD. However, although Gaul itself was to thereafter remain loyal, cracks were appearing in the political unity of Rome's governing figures – partly over concerns over the loyalty of Caesar's Gallic troops to his person rather than the state[207] – that were soon to drive Rome into a lengthy series of civil wars.

Triumvirates, Caesarian ascension, and revolt (53–30 BC)

By 59 BC an unofficial political alliance known as the

Gnaeus Pompeius Magnus to share power and influence.^[217] It was always an uncomfortable alliance given that Crassus and Pompey intensely disliked one another. In 53 BC, Crassus launched a Roman invasion of the Parthian Empire. After initial successes,^[218] he marched his army deep into the desert;^[219] but here his army was cut off deep in enemy territory, surrounded and slaughtered^[206] at the Battle of Carrhae^[220][221] in "the greatest Roman defeat since Hannibal"^[222] in which Crassus himself perished.^[223] The death of Crassus removed some of the balance in the Triumvirate and, consequently, Caesar and Pompey began to move apart. While Caesar was fighting against Vercingetorix in Gaul, Pompey proceeded with a legislative agenda for Rome that revealed that he was at best ambivalent towards Caesar^[224] and perhaps now covertly allied with Caesar's political enemies. In 51 BC, some Roman senators demanded that Caesar would not be permitted to stand for Consul unless he turned over control of his armies to the state, and the same demands were made of Pompey by other factions.^[225][226] Relinquishing his army would leave Caesar defenceless before his enemies. Caesar chose Civil War over laying down his command and facing trial.^[225]

The triumvirate was shattered and conflict was inevitable.

Pompey initially assured Rome and the senate that he could defeat Caesar in battle should he march on Rome.[227]^[228] However, by the spring of 49 BC, when Caesar crossed the Rubicon river with his invading forces and swept down the Italian peninsula towards Rome, Pompey ordered the abandonment of Rome.^[227][228] Caesar's army was still under-strength, with certain units remaining in Gaul,^[227] but on the other hand Pompey himself only had a small force at his command, and that with uncertain loyalty having served under Caesar.^[228] Tom Holland attributes Pompey's willingness to abandon Rome to waves of panicking refugees as an attempt to stir ancestral fears of invasions from the north.^[229] Pompey's forces retreated south towards Brundisium,^[230] and then fled to Greece.^[228][231] Caesar first directed his attention to the Pompeian stronghold of Iberia^[232] but following campaigning by Caesar in the Siege of Massilia and Battle of Ilerda he decided to attack Pompey in Greece.^[233][234] Pompey initially defeated Caesar at the Battle of Dyrrachium in 48 BC^[235] but failed to follow up on the victory. Pompey was decisively defeated in the Battle of Pharsalus in 48 BC^[236][237] despite outnumbering Caesar's forces two to one.^[238] Pompey fled again, this time to Egypt, where he was murdered^[196][239] in an attempt to ingratiate the country with Caesar and avoid a war with Rome.^[222][236]

Pompey's death did not see the end of the civil wars since initially Caesar's enemies were manifold and Pompey's supporters continued to fight on after his death. In 46 BC Caesar lost perhaps as much as a third of his army when his former commander

Metellus Scipio in the Battle of Thapsus, after which the Pompeians retreated yet again to Iberia. Caesar defeated the combined forces of Titus Labienus and Gnaeus Pompey the Younger at the Battle of Munda

in Iberia. Labienus was killed in the battle and the Younger Pompey captured and executed.

"The Parthians began to shoot from all sides. They did not pick any particular target since the Romans were so close together that they could hardly miss...If they kept their ranks they were wounded. If they tried to charge the enemy, the enemy did not suffer more and they did not suffer less, because the Parthians could shoot even as they fled...When Publius urged them to charge the enemy's mail-clad horsemen, they showed him that their hands were riveted to their shields and their feet nailed through and through to the ground, so that they were helpless either for flight or for self-defence."

Plutarch on the Battle of Carrhae[240]

Despite his military success, or probably because of it, fear spread of Caesar, now the primary figure of the Roman state, becoming an autocratic ruler and ending the Roman Republic. This fear drove a group of senators naming themselves

Mutina, defeated the forces of the consul Pansa, who was killed, but Antony was then immediately defeated by the army of the other consul, Hirtius. At the Battle of Mutina

Antony was again defeated in battle by Hirtius, who was killed. Although Antony failed to capture Mutina, Decimus Brutus was murdered shortly thereafter.

Octavian betrayed his party, and came to terms with Caesarians Antony and

Marcus Brutus and Cassius

. Although Brutus defeated Octavian, Antony defeated Cassius, who committed suicide. Brutus also committed suicide shortly afterwards.

Civil war flared again when the Second Triumvirate of Octavian, Lepidus and

Sextus Pompeius, the last focus of opposition to the second triumvirate, in the naval Battle of Naulochus

.

As before, once opposition to the triumvirate was crushed, it started to tear at itself. The triumvirate expired on the last day of 33 BC and was not renewed in law and in 31 BC, war began again. At the

Cleopatra in a naval battle near Greece, using fire to destroy the enemy fleet.^[244]

Octavian went on to become Emperor under the name Augustus[243] and, in the absence of political assassins or usurpers, was able to greatly expand the borders of the Empire.

Empire

Early to Middle (30 BC – 180 AD)

Imperial expansion (40 BC – 117 AD)

Secured from internal threats, Rome achieved great territorial gains in both the East and the West. In the West, following humiliating

Battle of the Weser River.^[255]

After Caesar's

Battle of Watling Street^[265][266] and went on to push as far north as central Scotland in the Battle of Mons Graupius.^[267][268] Tribes in modern-day Scotland and Northern England repeatedly rebelled against Roman rule and two military bases were established in Britannia to protect against rebellion and incursions from the north, from which Roman troops built and manned Hadrian's Wall.^[269]

On the continent, the extension of the Empire's borders beyond the Rhine hung in the balance for some time, with the emperor

Cnaeus Domitius Corbulo crossing the Rhine in 47 AD and marching into the territory of the Frisii and Chauci.^[270] Caligula's successor, Claudius, ordered the suspension of further attacks across the Rhine,^[270] setting what was to become the permanent limit of the Empire's expansion in this direction.^[2]

"Never was there slaughter more cruel than took place there in the marshes and woods, never were more intolerable insults inflicted by barbarians, especially those directed against the legal pleaders. They put out the eyes of some of them and cut off the hands of others; they sewed up the mouth of one of them after first cutting out his tongue, which one of the barbarians held in his hand, exclaiming At last, you viper, you have ceased to hiss!."

Florus on the loss of Varus' force[271]

Further east,

Battle of Tapae in AD 88 and a truce was drawn up.^[277]

Emperor Trajan recommenced hostilities against Dacia and, following an uncertain number of battles,

client states for some time, leading to less direct campaigning than in the west in this period.^[283]

The

Vologases I of Parthia

. Corbulo succeeded in returning Armenia to Roman client status, where it remained for the next century.

Year of the Four Emperors (69 AD)

In 69 AD, Marcus Salvius Otho, governor of Lusitania, had the Emperor Galba murdered^[285][286] and claimed the throne for himself.^[287][288] However, Vitellius, governor of the province of Germania Inferior, had also claimed the throne^[289][290] and marched on Rome with his troops.^[287][288] Following an inconclusive battle near Antipolis,^[291] Vitellius' troops attacked the city of Placentia in the Assault of Placentia, but were repulsed by the Othonian garrison.^[290][292]

Otho left Rome on March 14, and marched north towards Placentia to meet his challenger. In the

First Battle of Bedriacum,^[294] after which the Othonian troops fled back to their camp in Bedriacum,^[295] and the next day surrendered to the Vitellian forces. Otho decided to commit suicide rather than fight on.^[296]

Meanwhile, the forces stationed in the Middle East provinces of

Second Battle of Bedriacum,^[294][297] after which the Vitellian troops were driven back into their camp outside Cremona, which was taken.^[298] Vespasian's troops then attacked Cremona itself,^[299]

which surrendered.

Under pretence of siding with Vespasian,

Battle of Augusta Treverorum

.

Jewish revolts (66–135 AD)

The

Second Siege of Jerusalem.^[307]

In 115 AD, revolt broke out again in the province, leading to the second Jewish-Roman war known as the

Bar Kokhba's revolt

. Both were brutally crushed.

Struggle with Parthia (114–217 AD)

By the 2nd century AD the territories of Persia were controlled by the Arsacid dynasty and known as the

horse archers, Parthia was the most formidable enemy of the Roman Empire in the east. As early as 53 BC, the Roman general Crassus had invaded Parthia, but he was killed and his army was defeated at the Battle of Carrhae. In the years following Carrhae, the Romans were divided in civil war and hence unable to campaign against Parthia. Trajan also campaigned against the Parthians from 114 to 117 AD and briefly captured their capital Ctesiphon, putting the puppet ruler Parthamaspates on the throne. However, rebellions in Babylonia

and the Jewish revolts in Judea made it difficult to maintain the captured province and the territories were abandoned.

A revitalised Parthian Empire renewed its assault in 161 AD, defeating two Roman armies and invading Armenia and Syria. Emperor

Gaius Avidius Cassius were sent in 162 AD to counter the resurgent Parthia. In this war, the Parthian city of Seleucia on the Tigris was destroyed and the palace at the capital Ctesiphon was burned to the ground by Avidius Cassius in 164 AD. The Parthians made peace but were forced to cede western Mesopotamia to the Romans.^[308]

In 197 AD, Emperor Septimius Severus waged a brief and successful war against the Parthian Empire in retaliation for the support given to a rival for the imperial throne Pescennius Niger. The Parthian capital Ctesiphon was sacked by the Roman army, and the northern half of Mesopotamia was restored to Rome.

Emperor

Sassanid Empire

of Persia, which replaced Parthia as Rome's major rival in the East.

Throughout the Parthian wars, tribal groups along the Rhine and Danube took advantage of Rome's preoccupation with the eastern frontier (and the plague that the Romans suffered from after bringing it back from the east) and launched a series of incursions into Roman territories, including the Marcomannic Wars.

Late (180–476 AD)

Migration period (163–378 AD)

After Varus' defeat in Germania in the 1st century, Rome had adopted a largely defensive strategy along the border with Germania, constructing a line of defences known as

Alamanni,^[310]

first mentioned by Cassius Dio describing the campaign of Caracalla in 213 AD.

In around 166 AD, several Germanic tribes pushed across the Danube, striking as far as Italy itself in the Siege of Aquileia in 166 AD,^[308] and the heartland of Greece in the Sack of Eleusis.^[308]

Although the essential problem of large tribal groups on the frontier remained much the same as the situation Rome faced in earlier centuries, the 3rd century saw a marked increase in the overall threat,

Alamanni.^[314]

Gothic invasions

The assembled warbands of the Alamanni frequently crossed the limes, attacking Germania Superior such that they were almost continually engaged in conflicts with the Roman Empire, whilst Goths attacked across the Danube in battles such as the

Battle of Abrittus in 251 AD,^[315] and both Goths and Heruli ravaged the Aegean and, later, Greece, Thrace and Macedonia.^[314][316] However, their first major assault deep into Roman territory came in 268 AD. In that year the Romans were forced to denude much of their German frontier of troops in response to a massive invasion by another new Germanic tribal confederacy, the Goths, from the east. The pressure of tribal groups pushing into the Empire was the result of a chain of migrations with its roots far to the east:^[317] Huns from the Russian steppe attacked the Goths,^{[318][319][320]} who in turn attacked the Dacians, Alans and Sarmatians at or within Rome's borders.^[321]

The Goths first appeared in history as a distinct people in this invasion of 268 AD when they swarmed over the Balkan peninsula and overran the Roman provinces of Pannonia and Illyricum and even threatened Italia itself.

The Alamanni seized the opportunity to launch a major invasion of Gaul and northern Italy. However, the Visigoths were defeated in battle that summer near the modern Italian-Slovenian border and then routed in the

Battle of Ticinum.^[322] The Goths remained a major threat to the Empire but directed their attacks away from Italy itself for several years after their defeat. By 284 AD, Gothic troops were serving on behalf of the Roman military as federated troops.^[323]

The Alamanni on the other hand resumed their drive towards Italy almost immediately. They defeated

Battle of Reims,^[324] in 357 AD at the Battle of Strasbourg,^[325] in 367 AD at the Battle of Solicinium and in 378 AD at Battle of Argentovaria. In the same year the Goths inflicted a crushing defeat on the Eastern Empire at the Battle of Adrianople,^[326][327] in which the Eastern Emperor Valens was massacred along with tens of thousands of Roman troops.^[328]

At the same time,

Quinquegentanei^[323] raided Africa.^[330]

At the start of the 5th century, the pressure on Rome's western borders was growing intense. However, it was not only the western borders that were under threat: Rome was also under threat both internally and on its eastern borders.

Usurpers (193–394 AD)

An army that was often willing to support its general over its emperor, meant that if commanders could establish sole control of their army, they could usurp the imperial throne from that position. The so-called

Alexander Severus in 235 AD.^[331] However, Cassius Dio marks the wider imperial decline as beginning in 180 AD with the ascension of Commodus to the throne,^[332] a judgement with which Gibbon concurred,^[333] and Matyszak states that "the rot ... had become established long before" even that.^[332]

Although the crisis of the 3rd century was not the absolute beginning of Rome's decline, it nevertheless did impose a severe strain on the empire as Romans waged war on one another as they had not done since the last days of the Republic. Within the space of a single century, twenty-seven military officers declared themselves emperors and reigned over parts of the empire for months or days, all but two meeting with a violent end.[310]^[334] The time was characterized by a Roman army that was as likely to be attacking itself as it was an outside invader, reaching a low point around 258 AD.^[335] Ironically, while it was these usurpations that led to the breakup of the Empire during the crisis, it was the strength of several frontier generals that helped reunify the empire through force of arms.

The situation was complex, often with three or more usurpers in existence at once. Septimius Severus and Pescennius Niger, both rebel generals declared to be emperors by the troops they commanded, clashed for the first time in 193 AD at the Battle of Cyzicus, in which Niger was defeated. However, it took two further defeats at the Battle of Nicaea later that year and the Battle of Issus the following year, for Niger to be destroyed. Almost as soon as Niger's usurpation had been ended, Severus was forced to deal with another rival for the throne in the person of Clodius Albinus, who had originally been allied to Severus. Albinus was proclaimed emperor by his troops in Britain and, crossing over to Gaul, defeated Severus' general Virius Lupus in battle, before being in turn defeated and killed in the Battle of Lugdunum by Severus himself.

After this turmoil, Severus faced no more internal threats for the rest of his reign,

Alexander Severus was proclaimed emperor by both the Praetorian Guard and the senate who, after a short reign, was murdered in turn.^[337] His murderers were working on behalf of the army who were unhappy with their lot under his rule and who raised in his place Maximinus Thrax. However, just as he had been raised by the army, Maximinus was also brought down by them and despite winning the Battle of Carthage against the senate's newly proclaimed Gordian II, he too was murdered^[338] when it appeared to his forces as though he would not be able to best the next senatorial candidate for the throne, Gordian III

.

Gordian III's fate is not certain, although he may have been murdered by his own successor,

Battle of Chalons. The next decade saw an incredible number of usurpers, sometimes three at the same time, all vying for the imperial throne. Most of the battles are not recorded, due primarily to the turmoil of the time, until Diocletian, a usurper himself, defeated Carinus at the Battle of the Margus

and became emperor.

Some small measure of stability again returned at this point, with the empire split into a Tetrarchy of two greater and two lesser emperors, a system that staved off civil wars for a short time until 312 AD. In that year, relations between the tetrarchy collapsed for good and

Maximinus. From 314 AD onwards, Constantine defeated Licinius in the Battle of Cibalae, then the Battle of Mardia, and then again at the Battle of Adrianople, the Battle of the Hellespont and the Battle of Chrysopolis

.

Constantine then turned upon Maxentius, beating him in the

Battle of Milvian Bridge in the same year. Constantine's son Constantius II inherited his father's rule and later defeated the usurper Magnentius in first the Battle of Mursa Major and then the Battle of Mons Seleucus

.

Successive emperors

the Save and the Frigidus

.

Struggle with the Sassanid Empire (230–363 AD)

After overthrowing the Parthian confederacy,

Battle of Misikhe^[344] but Roman sources mention this battle only as an insignificant setback and suggest that Gordian died elsewhere.^[345]

Certainly, the Sassanids had not been cowed by the previous battles with Rome and in 253 AD the Sassanids under Shapur I penetrated deeply into Roman territory several times, defeating a Roman force at the Battle of Barbalissos^[345] and conquering and plundering Antiochia in 252 AD following the Siege of Antiochia.^[340][345] The Romans recovered Antioch by 253 AD,^[346] and Emperor Valerian gathered an army and marched eastward to the Sassanid borders. In 260 AD at the Battle of Edessa the Sassanids defeated the Roman army^[346] and captured the Roman Emperor Valerian.^[340][342]

By the late 3rd century, Roman fortunes on the eastern frontier improved dramatically. During a period of civil upheaval in Persia, emperor

Battle of Samarra during the retreat, possibly by one of his own men.^[347]

There were several future wars, although all brief and small-scale, since both the Romans and the Sassanids were forced to deal with threats from other directions during the 5th century. A war against Bahram V in 420 AD over the persecution of the Christians in Persia led to a brief war that was soon concluded by treaty and in 441 AD a war with Yazdegerd II was again swiftly concluded by treaty after both parties battled threats elsewhere.^[348]

Collapse of the Western Empire (402–476 AD)

Eastern Roman Empires

by 476

Many theories have been advanced in way of explanation for

decline of the Roman Empire, and many dates given for its fall, from the onset of its decline in the 3rd century^[349] to the fall of Constantinople in 1453.^[350]

Militarily, however, the Empire finally fell after first being overrun by various non-Roman peoples and then having its heart in Italy seized by Germanic troops in a revolt. The historicity and exact dates are uncertain, and some historians do not consider that the Empire fell at this point.

The Empire became gradually less Romanised and increasingly Germanic in nature: although the Empire buckled under Visigothic assault, the overthrow of the last Emperor

Romulus Augustus was carried out by federated Germanic troops from within the Roman army rather than by foreign troops. In this sense had Odoacer not renounced the title of Emperor and named himself "King of Italy" instead, the Empire might have continued in name. Its identity, however, was no longer Roman – it was increasingly populated and governed by Germanic peoples long before 476 AD. The Roman people were by the 5th century "bereft of their military ethos"^[351]

and the Roman army itself a mere supplement to federated troops of Goths, Huns, Franks and others fighting on their behalf.

Rome's last gasp began when the Visigoths revolted around 395 AD.[352] Led by Alaric I,^[353] they attempted to seize Constantinople,^[354] but were rebuffed and instead plundered much of Thrace in northern Greece.^[353][355] In 402 AD they besieged Mediolanum, the capital of Roman Emperor Honorius, defended by Roman Gothic troops. The arrival of the Roman Stilicho and his army forced Alaric to lift his siege and move his army towards Hasta (modern Asti) in western Italy, where Stilicho attacked it at the Battle of Pollentia,^[356][357] capturing Alaric's camp. Stilicho offered to return the prisoners in exchange for the Visigoths returning to Illyricum but upon arriving at Verona, Alaric halted his retreat. Stilicho again attacked at the Battle of Verona^[358] and again defeated Alaric,^[359] forcing him to withdraw from Italy.

In 405 AD, the Ostrogoths invaded Italy itself, but were defeated. However, in 406 AD an unprecedented number of tribes took advantage of the freezing of the Rhine to cross en masse: Vandals, Suevi, Alans and Burgundians swept across the river and met little resistance in the Sack of Moguntiacum and the Sack of Treviri,^[360] completely overrunning Gaul. Despite this grave danger, or perhaps because of it, the Roman army continued to be wracked by usurpation, in one of which Stilicho, Rome's foremost defender of the period, was put to death.^[361]

It is in this climate that, despite his earlier setback, Alaric returned again in 410 AD and managed to

Suebians, Visigoths and Burgundians.^[370]

"The fighting became hand-to-hand, fierce, savage, confused and without the slightest respite.... Blood from the bodies of the slain turned a small brook which flowed through the plain into a torrent. Those made desperately thirsty by their injuries drank water so augmented with blood that in their misery it seemed as though they were forced to drink the very blood which had poured from their wounds"

Jordanes on the Battle of the Catalaunian Plains[371]

The remainder of Rome's territory—if not its nature—was defended for several decades following 410 AD largely by

Patavium were sacked, and the Huns returned a year later. After brutally razing Aquileia, the Huns continued to move towards Rome. It was at this point that Pope Leo I managed to convince Attila

to leave.

Despite being the only clear champion of the Empire at this point, Aëtius was slain by the Emperor Valentinian III's own hand 2 years afterwards, leading Sidonius Apollinaris to observe, "I am ignorant, sir, of your motives or provocations; I only know that you have acted like a man who has cut off his right hand with his left".^[376]

Carthage, the second largest city in the empire, was

Romulus Augustus^[379] there was nobody to stop them. Odoacer happened to hold the part of the Empire around Italy and Rome but other parts of the Empire were ruled by Visigoths, Ostrogoths, Franks, Alans and others. The Empire in the West had fallen,^[370][379] and its remnant in Italy was no longer Roman in nature. The Eastern Roman Empire

and the Goths continued to fight over Rome and the surrounding area for many years, though by this point Rome's importance was primarily symbolic.

See also

• Military history of ancient Rome
• Military history of Italy

Citations