Aurelian was Roman emperor from 270 to 275 CE. He was one of the so-called Barracks Emperors, chosen by the Roman army during the turbulent period known as the Crisis of the Third Century (235-284 CE). 

 Besides victories against various invading tribes, he successfully restored the Roman Empire by bringing the breakaway territories of the Gallic Empire and Palmyra back under Roman control, which earned him the title restitutor orbis ('Restorer of the World'). In order to defend Rome, he ordered the construction of the Aurelian Walls around the city, many parts of which are remarkably well-preserved thanks to their continued use as defensive structures well into the 19th century CE.
Rise to Power
Lucius Domitius Aurelianus was born on 9 September 214/215 CE in either Serdica or Sirmium in the province of Moesia (later Dacia Ripensis). We know little of his early life, except that he was of modest origins, his father being a colonus to a senator named Aurelius. He had a successful career during the reign of Gallienus (r. 253-268 CE), but despite a flourishing career under that emperor, Aurelian nevertheless was part of the conspiracy that eventually assassinated him. With the accession of the usurper Claudius II immediately thereafter, Aurelian was made commander (dux) of the cavalry. Despite successes against the various barbarian invaders such as the Goths, Vandals, and Juthungi on the Danube frontier, Claudius' reign was cut short when he succumbed to the plague which had broken out in 270 CE. Initially, Claudius' brother Quintillus succeeded as emperor, but he seems to have only reigned for a few months. Aurelian soon rose as a rival to Quintillus, and when the former was hailed emperor by the troops, he disposed of his rival (September or November 270 CE).