Aurelian

Born around 214 in modest circumstances, likely in Moesia Superior, Aurelian entered the army in 235 and rose through the ranks to command the cavalry under Gallienus. After Gallienus' assassination in 268 and the brief reigns of Claudius Gothicus and his brother Quintillus, the Illyrian legions chose Aurelian as emperor in 270. He spent the next five years in constant campaign: defeating the Alamanni, Goths, Vandals, Juthungi, Sarmatians, and Carpi in succession, then conquering the breakaway Palmyrene Empire in the east in 273 and the Gallic Empire in the west the following year. He fortified Rome with the walls that still bear his name, abandoned the province of Dacia, and attempted monetary reforms to halt the currency's slide. He was also the first emperor to formalize the titles dominus et deus in official documents. He was killed around November 275, having reunited an empire that had nearly shattered under the weight of the Third Century Crisis.