Gallienus

Gallienus (253-268 CE) was a Roman Emperor during the Crisis of the Third Century (235-284 CE). The Empire broke apart during his reign.
He created the Comitatenses, which were cavalry units that could be sent at short notice anywhere within the Roman Empire.

1. BIOGRAPHICAL DETAILS

NAME:
- Publius Licinius Ignatius Gallienus
GALLIENUS’S DATES OF REIGN AS EMPEROR:
- 253 to 268 CE.
GALLIENUS’ DATE OF BIRTH AND DEATH:
- Born c.218 CE. Died 268 CE.
PLACE OF BIRTH AND DEATH:
- Possibly born in Falerii, Italia. Died in Milan, Italia.
GALLIENUS’ PREDECESSOR:
- Valerian
GALLIENUS’ SUCCESSOR:
- Claudius II Gothicus
HEIR TO THE THRONE BECAUSE:
- Proclaimed Emperor by his Father Valerian.
DIED PEACEFULLY OR ASSASSINATED:
- Assassinated by the Praetorian Guard whilst besieging Milan.
WHERE BURIED:
- His tomb is possibly located on the Via Appia near milepost IX.
GALLIENUS WAS FAMOUS BECAUSE:
- Gallienus lost Gaul and Palmyra, starting the break up of the Roman Empire during the Crisis of the Third Century. He faced continuous Revolts and Invasions during his reign.
- His Reforms laid the basis for the Dominate, Senators were forbidden to hold military Command which undermined their power to rebel against the Emperor when Governor of a Province.
- He created the Comitatenses, cavalry units that could be sent at short notice anywhere within the Roman Empire.
- Christianity: In 260 CE He passed the Decree of Toleration which restored the right of worship back to the Christian Church. This reversed the Valerian Persecution of his predecessor.

Gallienus was Valerian‘s son, and together they were co-Emperors. However, when Valerian went east to deal with the Parthian Empire, Gallienus remained in Rome and then proceeded to the Rhine Provinces, to better resist the Germanic invasions.
The Parthian War coupled with the Plague of Cyprian made the western Empire look weak and the Germanic Tribes recommenced their invasions.

Around 258-260 CE, Ingenuus, the Governor of Pannonia, revolted and declared himself Emperor. Gallienus left Cologne with his son Salolinus as co-Emperor, protected by the Praefectus Praetorio Silvanus, with Postumus commanding the Rhine Legions. He approached and successfully attacked Ingenuus, possibly at Sirmium, who was killed by his own soldiers.

Also in 258-259 CE There was an invasion by an alliance of the Franks, Alemanni and Juthungi, who crossed the Rhine, penetrated Gaul and reached Spain and Italy for the first time since Hannibal. The Alemanni reached Rome and were only held off by a hastily grouped citizen army working with the Praetorian Guard.
In 259 CE Postumus, after having defeated the Franks in Gaul, entered Italy and defeated the Alemanni as they were returning, at the Battle of Mediolanum. However, the Alemanni escaped back into Germany with their booty.

Regalianus, Governor of Pannonia, revolted and declared himself Emperor. He successfully defeated an invasion by the Sarmatians, but was then invaded by the Roxolani. His own soldiers assassinated him after only six months as Emperor.

260 CE The Revolt of Macrianus. He was a Tax Official under Valerian, and after the disastrous capture of Valerian by the Persians, he decided to leave his sons in charge of the East and march the remnants of the army towards Rome.
Gallienus sent the Comitatenses, his elite Cavalry commanded by General Aureolus, to defeat him, and Macrianus died in Thrace in 261 CE.

Meanwhile the Revolt of Postumus, who now controlled the Gallic Empire, was the biggest menace. Gallienus had to wait for Aureolus to return from Thrace before sending him to besiege Postumus in Gaul. Despite initial successes, Gallienus suffered a serious injury and Postumus was allowed to escape. The Gallic Empire was not recaptured until 274 CE.

In 262 CE, Aemilianus, the Prefect of Egypt Revolted, and Gallienus had to send another General, Theodotus, to defeat him at Thebes.

In 267-269 CE a series of devastating Germanic Invasions by the Goths and Heruli occurred mainly by sea. In 268 CE the a Gothic Fleet of 500 vessels entered the Black Sea and then the Aegean. Gallienus defeated the invaders on land in Thracia.
In 269 CE a much bigger Gothic Fleet of from 2-6,000 vessels and again ravaged the Black Sea and Aegean. This force was resoundingly defeated at the Battle of Naissus by Gallienus’ successor Claudius II Gothicus.

The Revolt of Aureolus. At some point Aureolus had lost his command of the Comitatenses, the elite cavalry regiment, and was sent by Gallienus to Raetia. Aureolus returned across the Alps and occupied the city of Mediolanum, retaking the command of the Comitatenses cavalry regiment based there. He then used the Milan Mint to issue coins with Postumus on one side and the Comitatenses on the other, inviting Postumus to become Roman Emperor. Postumus did not come or send assistance.
Gallienus was forced to return to Italy to deal with this latest threat, and successfully defeated him near Mediolanum. Gallienus then besieged Mediolanum, using Aureolus’ Comitatenses against him.

The Praefectus Praetorio Aurelius Heraclianus and Claudius II Gothicus conspired to have Gallienus assassinated during the siege of Mediolanum.
Aureolis surrendered to Gallienus’ successor Claudius II Gothicus only to be assassinated himself by Claudius’ Praetorian Guard, leaving Claudius unchallenged in Italy.