Gallic Wars
The Gallic Wars were a series of military campaigns waged by the Roman proconsul Julius Caesar against several Gallic tribes. Rome's war against the Gallic tribes lasted from 58 BC to 50 BC and culminated in the decisive Battle of Alesia in 52 BC, in which a complete Roman victory resulted in the expansion of the Roman Republic over the whole of Gaul (mainly present-day France and Belgium). While militarily just as strong as the Romans, the internal division between the Gallic tribes helped ease victory for Caesar, and Vercingetorix's attempt to unite the Gauls against Roman invasion came too late. The wars paved the way for Julius Caesar to become the sole ruler of the Roman Republic.
Gallienus
Gallienus (; ; c. 218 – September 268), also known as Gallien, was Roman Emperor with his father Valerian from 22 October 253 to spring 260 and alone from spring 260 to September 268. He ruled during the Crisis of the Third Century that nearly caused the collapse of the empire. While he won a number of military victories, he was unable to prevent the secession of important provinces. His 15-year reign was the longest since the 19-year rule of Caracalla.