Gallienus, Emperor of Rome

Gallienus is one of the Roman Emperors whose reputation has undergone considerable change over the centuries. Early historians regarded his reign as “one of the most ignoble and disastrous in the history of Rome” and himself as “indolent, profligate and indifferent to the public welfare” (to quote Smith’s Classical Dictionary) but modern research has credited him with some successes and qualities during a very difficult period of Roman history.

Publius Licinius Valerianus Egnatius Gallienus was probably born in 218, his father being the Emperor-to-be Valerian and his mother Egnatia Mariniana. When his father became Emperor in 253 he appointed Gallienus as his co-Emperor.

Gallienus was himself the father of three sons by his wife Cornelia Salonina. Two of these sons, Valerianus and Saloninus, were given the title of Caesar on Valerian’s accession, although they were probably aged only 15 and 11 respectively. The young princes were despatched to Illyria and Gaul respectively to create an imperial presence, but both were to die under suspicious circumstances.

Gallienus concentrated on securing the northern borders of the Empire while Valerian headed east to face the Persian threat. In this he was largely successful, but his main troubles were to come from internal revolts. One of these was from a commander named Ingenuus who had been entrusted with the care of young Valerianus. He declared himself Emperor after Valerianus died and Gallienus sought to demote him. Gallienus defeated Ingenuus in battle in 260, after which the usurper commited suicide.

Another revolt was launched by a general from Dacia named Regalianus, who attempted to seize power when Gallienus was busy elsewhere. He was, however, murdered by his own troops in 260.

A more serious threat was posed by general Marcus Postumus, who declared himself “Emperor of the Gauls” and remained in power until after Gallienus’s own death in 268. Gallienus believed that Postumus had been responsible for the death of his second son, Saloninus, and could never forgive him for that.

The number of rebellions throughout the reign of Gallienius was so great that the ancient “Historia Augusta” listed “thirty tyrants” who were pretenders at various times. Although later scholarship has disputed several of these names, the evidence that Gallienus was never secure on this throne is very strong.

A number of these revolts were occasioned in or around 260 when Gallienus became sole Emperor with the capture and disappearance of Valerian when fighting against the Sassanid Empire under Shapur.

One reason why the reign of Gallienus has had such a “bad press” among historians is that they have misunderstood the way in which Gallienus sought to deal with threats to his rule. He recognised that Rome could no longer be self-sufficient in organising its defence and that other powers had to be accommodated.

An example of co-operation of this kind is that with Palmyra (in modern Syria). The prince of Palmyra was Septimius Odaenathus who gave invaluable assistance to the Roman army after the capture of Valerian. He was himself threatened by the Sassanids and realised that an alliance with Rome was in his best interests. He had considerable success against Shapur and proclaimed himself “king of kings” but was always loyal to Gallienus. It is therefore unfair for Odaenathus to be counted among the “thirty tyrants” as he was never a threat to Roman rule.

However, Gallienus could not withstand the constant onslaughts for ever. In 268 he fell victim to a plot by his own senior officers who had staged a rebellion in northern Italy, and was killed while besieging Milan.

As sole ruler, Gallienus offered a new model for ruling the Empire in which the monolithic structure of the earlier Empire was broken down into largely self-contained units, often governed by commanders who had asserted themselves but who were nevertheless loyal to the Emperor. At least some of the thirty tyrants need to be seen in this light as opposed to being merely pretenders to the throne.

Although Gallienius’s personal reputation was smeared by many later commentators, he did have some qualities that should be cited in his favour. He was, for example, less interested in persecuting Christians than his father had been, and he granted freedom of worship to many Christian communities, returning property that had been seized during Valerian’s rule.

Gallienus had one of the most difficult reigns of any Emperor of Rome, but he achieved some major victories and proved himself to be a pragmatic ruler who responded well to the crises that arose.

© John Welford