Gaius Dillius Vocula

Gaius Dillius Vocula (†70 CE): Roman army commander, one of Rome's heroes during the Batavian revolt (69-70).

Gaius Dillius Vocula was born in Córdoba in Andalusia as the son of an otherwise unknown Roman knight named Aulus Dillius. His son probably was the first of his family to enter the Senate. It is likely that he was a protégé of Lucius Annaeus Seneca, the famous adviser of the emperor Nero, who advanced the careers of several promising men from Hispania and was a Cordoban too. Vocula was married to a woman named Helvia Procula, who may have been a relative of Seneca's mother.

His tombstone tells us that the young Andalusian served as a military tribune in the First legion Germanica, which was stationed at Bonn. After this, he was one of the four officials that were responsible for the maintenance of the roads, and his next position was that of quaestor in Bithynia-Pontus. He became tribune and praetor, and the emperor Nero made him commander of the Twenty-second legion Primigenia. This young legion was stationed at Mainz, where it defended the empire against the Germanic tribes that lived across the Rhine.

Unfinished portrait of Vitellius
Unfinished portrait of Vitellius

In 68, Nero committed suicide, and civil war broke out. One of the candidates for the imperial purple was the governor of Germania Inferior, Vitellius. With a large army, he marched on Rome and defeated his opponents. Now, the Rhine border was almost unguarded, and this was the moment for which the Batavians, a Romanized tribe that lived along the lower Rhine, had been waiting. For a variety of reasons (discussed here), they were discontent with Roman rule and revolted. In August 69, the Dutch river area changed into a war zone.

The overall commander of the Roman forces along the Rhine was the aged Marcus Hordeonius Flaccus. The historian Tacitus is extremely hostile to the old man: he portrays him as incapable and decadent, his Batavian opponent Julius Civilis as a noble savage, and Vocula as an example of Roman virtue. These are stereotypes, and we must use Tacitus' Histories critically. In fact Flaccus knew perfectly well what he had to do.


Julius Civilis was not a bad commander and was certainly a brilliant diplomat. Claiming to fight for another Roman pretender, Vespasian, he expelled the Roman garrisons from his tribe's territory. Flaccus did not know whether he was facing a local insurrection (which ought to be suppressed as soon as possible) or was fighting a civil war (in which case success would be dangerous when Vespasian became emperor). Since Vespasian was stronger than Vitellius, Flaccus was fighting an impossible war.

Nonetheless, he took measures. When the legions V Alaudae and XV Primigenia were besieged at Xanten, he had already reinforced them by at least one unit from the Sixteenth legion Gallica from Neuss, and hurried to its rescue with a large expeditionary force. It consisted of the Twenty-second legion of Gaius Dillius Vocula (from Mainz), the First legion Germanica from Bonn, auxiliary units and a small fleet.

However, the legionaries of the first legion refused to obey Flaccus' orders. He had one of the mutineers arrested, and proceeded to Cologne.

Among the legions there was growing resentment, and they had not been intimidated by the confinement of one solitary soldier. Indeed, the fellow actually tried to incriminate Flaccus, alleging that he had himself carried messages between him and Civilis, and was being got rid of on a trumped-up charge because he knew too much. Vocula showed remarkable firmness. He got up on a platform and ordered the man to be seized and taken away, still yelling, to execution. This gave the trouble-makers a shock, and the better sort obeyed orders. Then, as they called unanimously for Vocula to lead them, Flaccus handed over the command to him.note
The Low Countries in the Roman age
The Low Countries in the Roman age

We have already noted that we must read Tacitus critically. The real reason why the old Flaccus handed over the command of the advance guard (which is not the same as the command of the whole army), was that he suffered from gout. Besides, generals -ancient and modern- often have other responsibilities than military ones. Vespasian's army was on its way to Italy, and the political situation at home demanded Flaccus' attention. So, the Roman offensive paused at Krefeld. Tacitus offers all kinds of reasons for the delay: the soldiers had to receive additional training, the Cugerni (a tribe inside the empire that had sided with Civilis) had to be punished, they had to fight with enemies for the possession of a corn-ship... The real reason was that it was unwise to proceed to Xanten, which was, after all, besieged by what seemed to be adherents of Vespasian.

In the first days of November, the soldiers received bad news: their emperor Vitellius and his army -which was made up from units from the Rhine legions- had been defeated. Those at Krefeld personally knew many of the dead. This did little to improve the morale, especially since it was clear that Vitellius could no longer win the war. There was nothing to it than to go over to Vespasian's side.

On the other hand, the situation in the Rhineland now clarified. For the first time, it became clear that the Batavians were not really supporting Vespasian but were revolting to gain independence.

Julius Civilis knew that he had to destroy the army at Krefeld before it had united with the garrison of Xanten. If he had defeated the expeditionary force of Flaccus and Vocula, Xanten could no longer be relieved and would surrender. However,  the army of Flaccus and Vocula, even though it consisted of depleted legions, was too large to face in a regular battle. Flaccus and Vocula understood that the Batavian leader would try to catch them off-guard. And they could also surmise that he would do this on a moonless night, like the night of December 1/2, 69. Tacitus, however, wants us to believe that the Batavian attack came unexpectedly.

Vocula was unable to address his men or deploy them in line of battle. All he could do when the alarm sounded was to urge them to form a central core of legionaries, around which the auxiliaries were clustered in a ragged array. The cavalry charged, but were brought up short by the disciplined ranks of the enemy and forced back upon their fellows. What followed was a massacre, not a battle. The Nervian auxiliary units, too, were induced by panic or treachery to expose the Roman flanks. Thus the attack penetrated to the legions. They lost their standards, retreated within the rampart, and were already suffering heavy losses there, when fresh help suddenly altered the luck of the battle.
Some Basque auxiliary units [...] had been summoned to the Rhineland. As they neared the camp, they heard the shouts of men fighting. While the enemy's attention was elsewhere, they charged them from the rear and caused a widespread panic out of proportion to their numbers. It was thought that the main army had arrived, either from Neuss or from Mainz. This gave the Romans new heart: confident in the strength of others, they regained their own.note

The consequences of the Roman victory were enormous. Civilis had shown his true intentions and lost his best men, and nothing withheld Vocula from marching on Xanten and lifting the siege. (Flaccus remained at Neuss.) The camp's walls were strengthened, the ditches deepened, supplies brought in, the wounded taken away. But there was no opportunity to invade the country of the Batavians and retaliate, because the Usipetes and Chattians, Germanic tribes from the east bank of the Rhine, had crossed the river, and tried to besiege Mainz. It did not seem very serious, but Vocula did not to take risks. After all, Mainz was more important than the camp in the north. Therefore, the expeditionary force returned. Immediately, Civilis renewed the siege of an undergarrisoned but better equipped Xanten.

When the legionaries reached Neuss, Flaccus distributed money to celebrate the accession of Vespasian. As adherents of Vitellius, this was more than they had expected. These were the days of the Roman carnival, the Saturnalia, and the legionaries celebrated it with pleasure. It must have come as some sort of release after the tensions of the preceding weeks. However, the merrymaking was disturbed.

In a wild riot of pleasure, feasting and seditious gatherings at night, their old enmity for Hordeonius Flaccus revived, and as none of the officers dared to resist a movement which darkness had robbed of its last vestige of restraint, the troops dragged him out of bed and murdered him. The same fate was in store for Vocula, but he disguised himself in the darkness by dressing as a slave, and managed to get away.note

The assault  is one of the unexplained events during the Batavian revolt. (Go here for a possible explanation.) It was certainly not an act that all soldiers approved of, because Vocula could return to the camp and restore order. Then, he continued to the south and relieved Mainz (January 70).

However, the murder of Flaccus was a signal to the Trevirans and Lingones, ancient Gallic but romanized tribes living along the Mosel and upper Rhine, to join the Batavian revolt. The leader of this second insurrection was a man named Julius Sabinus, who claimed to be a descendant of Julius Caesar, and proclaimed himself emperor. With two commanders of auxiliary troops, Julius Classicus and Julius Tutor, he met with Julius Civilis in Cologne, and decided that the two officers would betray Vocula's army, which was by now -January 70- returning to Xanten.

Vocula did get wind of what was afoot through certain informants but with his legions under strength and disloyal, he was in no position to discipline the rebels by force. Caught between an unreliable army and a secret foe, he felt that the best course open to him was to pay back deception in its own coin, and wield the very weapon that threatened him. So he moved downstream to Cologne.


To this same city Claudius Labeonote made his escape after bribing his gaolers. This man undertook, if given a bodyguard, to go to the Batavians and force the better part of the tribe to return to their alliance with Rome. Receiving a small infantry and cavalry force, he made no attempt to carry out his venture against the Batavians, but induced a few Nervians and Baetasii to take up arms and conducted less a regular campaign than a series of stealthy raids against Batavian allies.note

The army of Claudius Labeo continued its guerilla for half a year, and forced Julius Civilis to divide his forces. When a large Roman expeditionary force, commanded by Quintus Petillius Cerialis, came across the Alps in the summer of 70, Civilis was too late to repel it. However, Vocula would not live to see it.

He now marched against the enemy and was already nearing Xanten when Classicus and Tutor went ahead, ostensibly to reconnoiter, and came to a firm understanding with the Batavian leaders. Then, for the first time, they broke away from the legions and built their own walled camp, though Vocula protested that Rome was not so racked with civil strife that the Trevirans and Lingones could afford to despise her. [....]
But when he saw that Classicus and Tutor persisted in their treachery, he turned around and returned to Neuss. The Gauls encamped three kilometers away on the flat ground. Centurions and soldiers passed to and fro between the camps, selling their souls to the enemy. The upshot was a deed of shame quite without parallel: a Roman army was to swear allegiance to the foreigner, sealing the monstrous bargain with a pledge to murder or imprison its commanders.note

Vocula knew that this was the end of the Roman presence in the Rhineland. If his army disintegrated, Xanten would fall, and the rebellion could spread through the Rhine valley. He paraded the remaining troops and delivered - according to Tacitus - a spirited address.

The speech was heard with emotions which varied between hope, fear and shame. Vocula withdrew and thought of committing suicide, but his freedmen and slaves foiled his desire to anticipate a hideous end. What happened was that Julius Classicus sent Aemilius Longinus, a deserter belonging to the First legion, and quickly secured his death.note

This was the end of Gaius Dillius Vocula, the commander of the Twenty-second legion Primigenia. After his death, his army surrendered, and in March, Xanten fell. However, not all was lost. Mainz had been relieved, and remained a Roman stronghold until Cerialis arrived. The fact that he could use this base made the recovery of the Rhineland a lot easier. Vocula's supreme command of the Rhine army had lasted for only a month, but had not been without merit.

Vocula was married to Helvia Procula, who erected her husband's tombstone, which was once at Rome but is now lost. He had a cousin named Gaius Dillius Aponianus from Córdoba, who also became a senator during the reign of the emperor Nero. During the civil war, he commanded the Third legion Gallica, which sided with Vespasian.

This page was created in 2002; last modified on 4 August 2015.