Aurelian (Latin: Lucius Domitius Aurelianus Augustus; 9 September 214 or 215 – September or October 275), was Roman Emperor from 270 to 275. During his reign, he defeated the Alamanni after a devastating war. He also defeated the Goths, Vandals, Juthungi, Sarmatians, and Carpi. Aurelian restored the Empire's eastern provinces after his conquest of the Palmyrene Empire in 273. The following year he conquered the Gallic Empire in the west, reuniting the Empire in its entirety. He was also responsible for the construction of the Aurelian Walls in Rome, and the abandonment of the province of Dacia. His successes effectively ended the Roman Empire's Crisis of the Third Century, earning him the title Restorer of the World. Although Domitian was the first Emperor who had demanded to be officially hailed as dominus et deus (master and god), these titles never occurred in written form on official documents until the reign of Aurelian.

Aurelian was born in Serdica (today Sofia in Bulgaria) in Moesia or what was later called Dacia Ripensis to an obscure provincial family; his father was tenant to a senator named Aurelius, who gave his name to the family. Aurelian probably joined the army in 235 at around age twenty. He distinguished himself in several wars during the tumultuous mid-century; his successes as a cavalry commander ultimately made him a member of emperor Gallienus' entourage. In 268, Aurelian and his cavalry participated in general Claudius' victory over the Goths at the Battle of Naissus. Later that year Gallienus traveled to Italy and fought Aureolus, his former general and now usurper for the throne. Driving Aureolus back into Mediolanum, Gallienus promptly besieged his adversary in the city. However, while the siege was ongoing the Emperor was assassinated. One source says Aurelian, who was present at the siege, participated and supported general Claudius for the purple – which is plausible.