Gallienus

Publius Licinius Egnatius Gallienus was a Roman emperor who ruled from 253 to 268. He lived during the Crisis of the Third Century. This was a dangerous period when the Roman Empire nearly collapsed. Gallienus ruled alongside his father, Valerian, for seven years. After Valerian was captured, Gallienus ruled alone for eleven years. His 15-year reign was the longest in fifty years.

Gallienus was born into a wealthy senatorial family. His father was Emperor Valerian and his mother was Mariniana. Some inscriptions suggest he may have been born in Falerii. He married Cornelia Salonina about ten years before he became emperor.

They had three sons: Valerian II, Saloninus, and Marinianus. The lives of his children were often tied to the chaos of his reign. Valerian II died in 258. Saloninus was murdered in 260. Marinianus was killed in 268, shortly after his father's death.

When Valerian became emperor in 253, he and Gallienus divided the empire. This division was necessary because the empire was massive. It also helped them manage many different threats at once. Valerian went to the East to face the Sasanian Empire. Gallienus stayed in the West to defend against Germanic tribes. He spent much of his time in the Rhine provinces, such as Germania Inferior and Germania Superior.

Gallienus faced many internal threats from people called usurpers. A usurper is someone who tries to take imperial power illegally. Between 258 and 260, a governor named Ingenuus declared himself emperor. Gallienus reacted quickly by crossing the Balkans. He led a new cavalry corps called the comitatus to defeat Ingenuus at Mursa.

Later, a man named Regalian also revolted in the Balkans. Regalian held power for about six months before he was killed by the Roxolani.

External invasions also pressured the empire's borders. Germanic tribes like the Franks and the Alemanni attacked Roman lands. The Franks broke through the Rhine and reached as far as southern Spain. The Alemanni invaded through the area between the Rhine and the Danube. They even entered Italy, which had not happened in 500 years.

Gallienus defeated the Alemanni at the battle of Mediolanum in 259. This victory was decisive because the Alemanni did not attack for ten years.

In the East, the situation was even more difficult. In 260, the Sasanian Empire defeated the Romans at the Battle of Edessa. The Sasanian ruler, Shapur I, captured Emperor Valerian.

This event caused massive chaos and civil war. Two men, Macrianus Major and his son Quietus, tried to take power as usurpers. They led an army of 30,000 men toward Europe. Gallienus eventually defeated them in a battle in 261 or 262. However, Gallienus could not stop the formation of the breakaway Gallic Empire under the general Postumus.

Gallienus's life ended during a siege in 268. A usurper named Aureolus had declared himself emperor in Mediolanum. Gallienus defeated Aureolus outside the city and began a siege. During this time, Gallienus was assassinated by an officer named Cecropius. This was part of a conspiracy. His death marked the end of a long and difficult era of Roman history.