Aurelian ( 9 September c. 214 – c. November 275) was a Roman emperor from 270 to 275 during the Crisis of the Third Century. During his reign, he won an unprecedented series of military victories which reunited the Roman Empire after it had nearly disintegrated under the pressure of barbarian invasions and internal revolts. For his success in restoring the Empire's territorial integrity, Aurelian was honored with the title Restitutor Orbis ("Restorer of the World").
 
Aurelian was chosen Roman emperor by the Illyriciani as one of themselves. 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, the abandonment of the province of Dacia, and monetary reforms attempting to curb the devaluation of the Roman currency.
 
The deaths of the Sassanid Kings Shapur I (272) and Hormizd I (273) in quick succession, and the rise to power of a weakened ruler (Bahram I), presented an opportunity to attack the Sassanid Empire, and in 275 Aurelian set out for another campaign against the Sassanids. On his way, he suppressed a revolt in Gaul – possibly against Faustinus, an officer or usurper of Tetricus – and defeated barbarian marauders in Vindelicia (Germany).
However, Aurelian never reached Persia, as he was murdered while waiting in Thrace to cross into Asia Minor. As an administrator, he had been strict and had handed out severe punishments to corrupt officials or soldiers. A secretary of his (called Eros by Zosimus) had told a lie on a minor issue. In fear of what the emperor might do, he forged a document listing the names of high officials marked by the emperor for execution and showed it to collaborators. The notarius Mucapor and other high-ranking officers of the Praetorian Guard, fearing punishment from the emperor, murdered him shortly after October 275 (Tacitus began his reign in November or December), in Caenophrurium, Thrace.[68][36]