Background
The exact birth date of Gallienus is unknown. The Greek chronicler John Malalas and the Epitome de Caesaribus report that he was about 50 years old at the time of his death, meaning he was born around 218.
The exact birth date of Gallienus is unknown. The Greek chronicler John Malalas and the Epitome de Caesaribus report that he was about 50 years old at the time of his death, meaning he was born around 218.
Gallienus was made coemperor with his father, the Emperor Valerian, in 253 and became sole emperor after Valerian was captured by the Persians in 260. Although the power and prestige of Rome reached a low point during his reign, it must be said in justice to Gallienus that he was faced with an impossible situation. With the imperial finances in a chaotic state and the army badly in need of reorganization, a policy of expediency dictated that Gallienus should withdraw his forces from Gaul and the East to defend Rome and the central part of the Empire. To accomplish this, he tacitly allowed Gaul in the West and Palmyra in the East to become independent. Criticized because of his fondness for Greek culture and blamed for the disintegration of the Roman Empire, Gallienus was assassinated by his own officers in 268. He had, however, already laid the foundations for a military reorganization which made it possible for his successors to restore the unity of the Empire.
Pablius Gallienus contributed to military history as the first to commission primarily cavalry units, the Comitatenses, that could be dispatched anywhere in the Empire in short order. This reform arguably created a precedent for the future emperors Diocletian and Constantine I. The biographer Aurelius Victor reports that Gallienus forbade senators from becoming military commanders. This policy undermined senatorial power, as more reliable equestrian commanders rose to prominence. In Southern's view, these reforms and the decline in senatorial influence not only helped Aurelian to salvage the Empire, but they also make Gallienus one of the emperors most responsible for the creation of the Dominate, along with Septimius Severus, Diocletian, and Constantine I.
Gallienus married Cornelia Salonina about ten years before his accession to the throne. She was the mother of three princes.
