Legio XV Primigenia

Legio XV Primigenia: one of the Roman legions. The surname Primigenia is one of the titles of the goddess Fortuna.


This legion was founded by the emperor Caligula in 39, who needed extra forces for his campaign in Germany. It was called after the favorite goddess of the emperor ("Primigenia" is a title of Fortuna), but the title was almost never used. It is absent from the inscriptions and is only rarely used by authors like Tacitus and Plutarch of Chaeronea. The number seems to have been suggested by the fact that it was supposed to share a base with XIV Gemina.

In the Autumn of 39, the Fifteenth legion and its twin XXII Primigenia marched across the Alps to the Middle Rhine, where they saw their first action in the neighborhood of Wiesbaden. According to our sources, Caligula's campaigns on the east bank of the Rhine were not really important, but archaeological finds suggest that this is not true. For example, one of the recruits, Lucius Varius Sacco of Milan, died in Mainz after only one year of service, which almost certainly means that he was killed in action. He was twenty-five.

Later, XV Primigenia was stationed with the Fourteenth at Mainz in Germania Superior. Perhaps this had been supposed to be its base all along, because the number XV may have been chosen to fit XIV. The tombstone of a mounted legionary suggests that one cavalry subunit was at least temporarily based at Worms.

Tomb of Lucius Varius Sacco (Mainz)

In 43, the emperor Claudius, who had succeeded Caligula in 41, invaded Britain and took some legions with him. This left vacancies, and XV Primigenia moved to Xanten in the northern province of Germania Inferior, which had been evacuated by XXI Rapax.

At Xanten, the Fifteenth shared its legionary base with the Fifth Legion Alaudae. Archaeological finds enable us to establish that the fifteenth legion occupied the eastern, left-hand side of the fort and the Fifth the western, right-hand half. There were also cavalry men living at Xanten; one of them was Pliny the Elder, who was to become famous as the author of a well-known encyclopaedia, the Natural History.

XV Primigenia and V Alaudae must have been part of the expeditionary force that was led against the Frisians and Chauci by the Roman general Gnaeus Domitius Corbulo in 47. The operation was successful, but the emperor Claudius ordered the Romans to keep the Rhine as the empire's frontier. The soldiers were ordered to build fortifications along the Rhine and dig a canal from Matilo (Leiden) to the capital of the Cananefates, Voorburg. This canal still exists.

Dedication to the emperor Nero, by the commander of XV Primigenia, Publius Sulpicius Scribonius Rufus.

In 67, the position of the emperor Nero became untenable. Many senators were discontent and several governors discussed his removal. Among these were Lucius Clodius Macer of Africa (who recruited the I Macriana Liberatrix) and Gaius Julius Vindex of one of the provinces in Gaul, who supported the governor of Hispania Tarraconensis, Servius Sulpicius Galba, when he declared that he wanted to dethrone Nero.

This was treason, and the army of Germania Inferior (I Germanica, V Alaudae, XV Primigenia and XVI Gallica) knew what it had to do: it marched to the south and defeated Vindex. The soldiers expected to be rewarded, but were disappointed: Galba and a newly recruited Seventh Legion marched on Rome, the Senate recognized him, and Nero committed suicide (June 68). What had been examplary behavior, was now explained as an attempt to obstruct the accession of the new emperor.

Rooftile of XV Primigenia (Xanten)

Therefore, the army of Germania Inferior proclaimed their own commander, Vitellius, emperor and started to march on Rome (January 69). During the winter, they crossed the Alps.

Immediately, there was panic in the capital, a senator named Otho was proclamed ruler of the empire, and Galba was lynched. A soldier of the Fifteenth who happened to be present, one Camurius, gave the final blow.

Tombstone of Pompeius, soldier of XV Primigenia

Now the civil war was between Vitellius and Otho, and soldiers of the Fifteenth were present when the Vitellians defeated the Othonians in April in northern Italy. Now Vitellius started his reign. However, in the east, general Vespasian had also decided to make a bid for power. The two armies clashed near Cremona in northern Italy, and the Rhine army was defeated by the soldiers of Vespasian.

Meanwhile, in Germania Inferior, a disaster was in the making. The Batavians felt offeneded because Galba had dismissed his Batavian bodyguard, and revolted. A Roman expeditionary force, consisting of the remains of V Alaudae and XV Primigenia, was defeated near Nijmegen, and in the Autumn of 69, these two legions found themselves besieged at Xanten. Although I Germanica, XVI Gallica and a legion from Germania Superior, XXII Primigenia, tried to rescue them, the two legions at Xanten were forced to surrender in March 70. The rebels struck coins to commemorate their victory. Not much later, I Germanica and XVI Gallica surrendered as well.

Coin of the Gallic Empire, celebrating the surrender of XV Primigenia

It took several months before the new emperor Vespasian could send a strong Roman army to recover the Rhineland, commanded by his relative Quintus Petillius Cerialis. The legions XVI Gallica and IIII Macedonica, which had guarded Mainz, were renamed (XVI Flavia Firma and IIII Flavia Felix); the remains of I Germanica were added with Galba's Seventh legion and became known as VII Gemina ("the twin legion"). V Alaudae and XV Primigenia, however, were never reconstituted.


This page was created in 2002; last modified on 11 October 2020.