Year of the Four Emperors, Roman Civil Wars


AD 69 (Year of the Four Emperors, Roman Civil Wars) – The power struggle between Marcus Salvius Otho, the former governor of Lusitania, and Aulus Vitellius, governor of Germania Inferior (Lower Germany), was the latest chapter in the Roman civil war which followed the death of the Julio-Claudian Emperor Nero in the summer of AD 68. The assassination of his immediate successor, Galba, the following January signalled the beginning of a months-long internecine struggle between these two men. The contest between Otho and Vitellius was decided in the Padus (Po) Valley in northern Italy. The first significant clash came at Placentia (Piacenza). Here, the legions of Vitellius’ lieutenant, Caecina, besieged the city in an attempt to force the capitulation of the resident Othonian forces led by Vestricius Spurinna. Once his army was across the Padus River, Caecina’s legions attacked the community, but were unsuccessful in breaching its walls and suffered heavy losses by the end of the day’s action. His army resumed the investment the next morning, this time with the aid of siege-works – fascines, manlets and sheds to mine the walls – but still failed to make progress against the defenders. Unable to overcome the city’s defences by storm, Caecina ultimately abandoned the assault, re-crossed the river and marched against Cremona some 20 miles (32km) away.

Locus Castorum

AD 69 (Year of the Four Emperors, Roman Civil Wars) – The death of Roman Emperor Nero in the summer of AD 68 proved the catalyst for a violent power struggle in the Empire that eventually pitted various Roman legions against one another in open civil war. Following the demise of the Julio-Claudian dynasty, Servius Sulpicius Galba briefly served as emperor from June of AD 68 until the following January, before his assassination again plunged the Empire into chaos. Two other contenders now openly sought the emperorship: Marcus Salvius Otho, the former governor of Lusitania, and Aulus Vitellius, governor of Germania Inferior (Lower Germany). The contest between these two pretenders was ultimately decided in the Po Valley of northern Italy. The first clash occurred at Locus Castorum, a location some 12 miles (19.3km) from the town of Cremona. Vitellian forces encountered an Othonian army led by the general Suetonius Paulinus. With the approach of Otho’s troops, the legatus Aulus Caecina Alienus prepared an ambuscade for the enemy. Deploying auxiliary troops in some woods near the road, he sent his cavalry with instructions to provoke an engagement and then feign retreat in order to draw the Othonians into the trap. The opposing generals soon learned of the intended ambush and approached the location with caution, though still intent on pursuing battle. Paulinus immediately assumed command of the infantry, while Marius Celsus led the cavalry. Before reaching the location of Caecina, Otho’s commanders assembled their army into battle formation. On the left flank, they positioned a vexillation of the Legio XIII Gemina, four cohorts of auxiliary infantry and 500 auxiliary cavalry. Opposite these troops, on the right flank, were arrayed the Legio I Adiutrix, a pair of auxiliary infantry cohorts and 500 horse. In the centre, spanning the road, were three praetorian cohorts. To the rear, Paulinus stationed a reserve of 1,000 Praetorian and auxiliary cavalry. As the Othonians advanced, a portion of the Vitellian line broke and fled. Celsus suspected a trick, and in turn initiated a feigned withdrawal which lured some of the enemy from cover. Caecina’s troops gave chase and quickly found themselves constrained by legionary cohorts to their front and auxiliary infantry on the flanks. Before they could properly react, the prompt arrival of Celsus’ cavalry closed any avenue of retreat toward Cremona. While the two sides faced one another, Paulinus paused long enough to redress his line and formulate a plan of attack. The delay offered Caecina’s men opportunity to seek the relative safety of nearby vineyards and a small grove of woods. When the Othonian army was properly arrayed, Paulinus ordered his battle line to charge. The attack proved irresistible. Even with the piecemeal arrival of reinforcements, the auxiliary cohorts of Caecina were flushed from the tangle of vines and tree cover and completely routed. The defeated remnants of the army thereafter retreated to Cremona.

Forum Julii

AD 69 (Year of the Four Emperors, Roman Civil Wars) – During the Roman civil war between Emperor Otho and Aulus Vitellius, governor of Germania Inferior (Lower Germany), envoys from Gallia Narbonensis appealed to the Vitellian general, Fabius Valens, for protection in the province from a marauding Othonian fleet. In response, he dispatched a force of auxilia, both infantry and cavalry, to secure the region, which had earlier declared its allegiance for Vitellius. A portion of these troops bivouacked at the port of Forum Julii (Frejus) to help secure the unprotected coast from indiscriminate raiding by the enemy. Upon the approach of an Othonian army, the Vitellians prepared for battle. They deployed twelve turmae of cavalry, including Trevirian horsemen, and a select detachment of infantry. These were reinforced by local auxiliaries, 500 Pannonian recruits not yet formally enrolled into service and one Ligurian cohort. Once the two armies began assembling for battle, the Vitellians, who were strongest in cavalry, formed two lines; the mounted squadrons in front, followed by the infantry in close ranks. The Ligurian auxiliaries were located on adjacent high ground. Opposing the Vitellians was a numerically superior army that included several cohorts of Praetorian infantry and a mixed contingent of marines and local militia. These were deployed over a level area extending inland from the coast. Nearby, the Othonian fleet was anchored close to shore, its ships facing the battlefield in order to better provide support for the army. The Trevirian cavalry opened the contest with an imprudent charge against the Praetorians, which not only failed to disrupt the formation of veteran infantry, but needlessly exposed their flank to the fire of slingers. While both armies were fully engaged in the struggle, the Othonian fleet attacked the enemy’s rear. The action trapped the Vitellians, who were only able to avoid complete destruction with the onset of nightfall. The Othonians returned to camp following this victory, unaware that the enemy, though defeated, was prepared to regroup for a second battle. After receiving fresh reinforcements, including two cohorts of Tungarian auxilia, the Vitellians launched a surprise assault that penetrated their opponents’ encampment and forced the Othonians to abandon their defences and rally on a nearby hill. The resulting struggle was long and stubbornly contested, and both sides accrued heavy casualties. The battle finally ended when intense missile fire overwhelmed the determined resistance of the Tungrian infantry and put the Vitellians to flight once again. An effort by the Othonians to underscore their victory with a vigorous chase was abruptly stopped when the enemy horse wheeled around and briefly surrounded their pursuers. Both armies thereafter withdrew, the Vitellians to nearby Antipolis (Antibes) and the emperor’s forces further up the coast to Albingaunum (Albenga) in Liguria.


AD 69, 14 April (Year of the Four Emperors, Roman Civil Wars) – The death of Emperor Nero in early June of AD 68 resulted in open civil war throughout the Roman Empire. Following the assassination of the hastily chosen Emperor Galba, the armies of his successor, Marcus Salvius Otho, clashed with those of Aulus Vitellius, governor of Germania Inferior (Lower Germany), near the northern Italian communities of Cremona and Bedriacum (Calvatone). In a preliminary contest outside the village of Locus Castorum, an Othonian army led by the general Suetonius Paulinus defeated an inferior rival force commanded by Aulus Caecina Alienus. The defeated Vitellian troops fled to Cremona, where they were soon joined by an army under Fabius Valens. As the two sides prepared for the coming engagement, Otho’s principal commander – his brother, Titianus, and the prefectus, Proculus – rejected the counsel of Paulinus and the legatus Marius Celsus to await reinforcements and instead elected to immediately force a major action outside of Cremona. The emperor withdrew to the safety of Brixellum (Brescello), accompanied by a strong force of his bodyguards, cavalry and Praetorian Guardsmen. The two armies arrayed for battle near Cremona. The forces of Vitellius possessed the advantage of both strength and numbers, and their greater morale permitted the legions to quickly form into orderly ranks, while confusion slowed the development of the Othonian line. The fighting concentrated along the raised causeway of the Via Postumia, a road situated on the left bank of the Padus (Po) River. In an open plain bounded by the river and road, intense fighting erupted between Vitellius’ veteran Legio XXI Rapax from Germania Superior (Upper Germany) and the less experienced Legio I Adiutrix. The First Legion, consisting of marines levied from the fleet at Ravenna, inflicted heavy casualties on the leading ranks of the Twenty-first and temporarily captured its eagle before a ferocious counter-attack drove back the Legio I with heavy losses, including its legate, Orfidius Benignus. At the same time, Vitellius’ Legio V Alaudae from Germania Inferior (Lower Germany) routed the Legio XIII Gemina based in Pannonia. On another part of the battlefield, the Vitellians attacked Otho’s XIV Gemina after successfully isolating the legion with superior forces. The general struggle remained undecided for some time until Caecina and Valens reinforced their legions by the application of reserves. The Vitellian effort was further strengthened with the arrival of Batavian auxilia under Varus Alfenus. Fresh from their victory over Othonian forces at the Padus, the Batavians immediately launched a concentrated assault against the enemy’s flank. This attack, together with continued pressure brought against the opposing ranks by the Vitellian legions, caused Otho’s centre to collapse. The loss of this central formation triggered a total rout. Both victors and vanquished were temporarily slowed by the carnage on the Via Postumia as each departed the field in the direction of Bedriacum, approximately 15 miles (24km) away. As the army of Vitellius reached the town’s fifth milestone, Caecina and Valens ended the pursuit. Total Roman dead amounted to over 40,000.


AD 69, 24 October (Year of the Four Emperors, Roman Civil Wars) – The Roman civil war that followed the Emperor Nero’s death in early summer of AD 68 resulted in the rapid manifestation of four claim- ants to the imperial purple by the spring of the following year. The power struggle eventually led to the assassination of Emperor Galba in January AD 69 after only seven months in power; the suicide of his successor Otho following his army’s defeat at Cremona in April; and the emergence of a violent contest between Aulus Vitellius, governor of Germania Inferior (Lower Germany), and Titus Flavius Vespasianus, the general appointed by Nero to crush an ongoing revolt in Judaea. Near the town of Bedriacum (Calvatone) in northern Italy, legions loyal to Vitellius and Vespasian joined in a violent battle to determine the future of the Empire. Following a sharp but largely inconclusive engagement on the first day, both armies prepared for a major battle that night. Shortly after dusk, the Flavian commander Marcus Antonius Primus drew up his army across the Via Postumia, an elevated roadway which extended between the towns of Cremona and Bedriacum, and generally followed the left bank of the Padus (Po) River. He positioned the Legio XIII Gemina on the causeway, and on the left flank in an open plain he deployed the Legio VII Galbiana and the Legio VII Claudia. To the right, Antonius stationed the Legio VIII Augusta on a secondary road. It was joined by the Legio III Gallica, which found itself hampered on the far right by its placement among dense thickets. A detachment of praetorians was then drawn up next to the Third Legion and auxiliary cohorts were posted on each wing. The Flavian cavalry, numbering some 4,000, secured the flanks and rear of the entire formation. Lastly, ahead of the legions ranged a select force of Suebian tribesmen.

Opposite Antonius’ front line, the darkness heavily obscured a formidable Vitellian battle formation. The approaching army was presently leaderless, as its general, Aulus Caecina Alienus, was in irons after plotting to defect to the Flavians. The absence of their senior commander, combined with the dark of night, served to create some initial confusion within the ranks of the Vitellians. On the extreme right, the Legio IIII Macedonica advanced in the company of the Fifth and Fifteenth legions, which were stationed in the centre along with vexillations of the Legio IX Hispana, Legio II Augusta and the Legio XX Valeria Victrix. On the left, the Sixteenth and First legions were joined by the Legio XXII Primigenia. Within the ranks of each was included a liberal distribution of soldiers from the depleted cohorts of the Legio XXI Rapax and Legio I Italica. Completing the arrangement was the army’s cavalry and auxilia, which were arrayed around the main body of heavy infantry. Some distance from Bedriacium, the contending armies met in a decisive confrontation. The battle lasted throughout the night, and proved to be a savage, confusing struggle whose outcome remained uncertain until dawn when the men of the Legio III Gallica, imbued with a certain Syrian custom after many years of service in the orient, turned and saluted the rising sun. The Vitellians misunderstood the gesture, and concluded that the Third Legion was acknowledging the arrival of reinforcements. Using the dissemination of this misinformation to best advantage, the Flavian cohorts vigorously advanced as if supported by fresh divisions. The ruse worked to further demoralize an enemy already weakened by a lack of leadership, and Antonius seized the opportunity to launch an assault against the opposing line. The forceful attack broke the Vitellian formation, and a subsequent attempt to reform proved futile because the oppressed cohorts were driven back among their own supply wagons and artillery. Unable to recover, Vitellius’ forces dissolved into headlong retreat toward Cremona, pursued by the victorious troops of Vespasian.

Via Salaria

AD 69, 20-21 December (Year of the Four Emperors, Roman Civil Wars) – In preparation for marching his legions into Rome, Flavian general Marcus Antonius Primus sent an advance column of 1,000 cavalry along the Salarian Way with orders to enter the north-eastern part of the city and secure the Colline Gate. As the detachment of horsemen led by Quintus Petilius Cerialis approached their destination, they encountered a Vitellian force, consisting of both infantry and cavalry, blocking the Via Salaria. The resulting battle occurred in a developed area outside the city walls where the maze of buildings, gardens and winding streets proved a liability for Cerialis’ troops. At the same time, the familiar surroundings permitted the Vitellians to exploit the situation to best tactical advantage and eventually put the enemy to ?ight. The subsequent pursuit by the victors lasted only as far as the town of Fidenae, some 5 miles (8km) north of Rome on the same highway.


AD 69, 20-21 December (Year of the Four Emperors, Roman Civil Wars) – The Roman civil war that followed the death of Nero in the early summer of AD 68 climaxed eighteen months later in the autumn of 69 with an intense struggle between the armies of Emperor Aelius Vitellius and his challenger, the veteran legatus, Titus Flavius Vespasianus. Following the victory of Flavian legions at Bedriacum (Calvatone) in northern Italy, Vespasian’s lieutenant, Marcus Antonius Primus, marched south toward Rome with the intention of finishing the conflict. Advancing along the Via Flaminia, Antonius’ army arrived in late evening at Saxa Rubra, a village located some 6 miles (9.6km) north of the capital. Here he learned that a 1,000-man cavalry detachment, dispatched by him earlier under the com- mand of Quintus Petilius Cerialis, had been defeated on the Via Salaria near Rome. Further, it appeared the preponderance of popular support in the city was for Vitellius. While the army halted temporarily on the far side of the river, a senatorial delegation arrived with a peace proposal for Antonius, soon followed by Vestals bearing letters from Vitellius requesting the Flavians delay their march until the next day. The general was inclined to accede to the request and camp near the Milvian Bridge, but the legions refused to stop their advance and demanded Antonius continue on despite the late hour. Once the Flavians resumed their march, they divided into three columns: one force continuing along the Flaminian Way, a second to the right of the highway following the banks of the Tiber and a third approaching the Colline Gate on the north-eastern side of the city. The Vitellians countered by deploying troops ahead of each of these columns. As a result, widespread fighting occurred near the northern and north-eastern walls of the city, on the Campus Martius and in the Sixth, or Alta Semita, Region of the city. In addition, Antonius’ legions encountered particularly stiff resistance at the Castra Praetoria, which only ended after the complete destruction of the veteran praetorian cohorts of the emperor. After hours of combat, the Flavian divisions finally gained control of the city in late afternoon. By that time Vitellius was dead, murdered by soldiers earlier in the day.

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