Explanation: Aurelian was a Roman military officer during the Crisis of the Third Century, a period in which the Roman Empire seemed on the verge of disintegration. He was, in fact, born during the Crisis, and had spent his ~50 years of life watching the Empire fall apart piece by piece. By the time the army acclaimed him Emperor, the Empire had been split into 3 - or 4 if you include Aurelian himself. A "Gallic Empire" which had been extant for ~20 years at that point, a rival Emperor in Rome, and the Palmyrian Kingdom in the East; all of which claimed rightful ownership of the whole of the Roman Empire.

Within five years, Aurelian would restore all of those rival factions to unity under the Roman Empire, and himself as Emperor, beating back barbarian tribes and warding off an incursion of the Persian Empire in the process. For this achievement, he became known as Restitutor Orbis - 'Restorer of the World'.

He would be assassinated by a cabal of corrupt officials due to his strong anti-corruption stance. The Empire's territorial integrity would remain 'restored', but the Imperial government would continue its decline, culminating in the Emperor Diocletian a decade-and-a-half after Aurelian's death, who disregarded the Senate entirely and demanded to be worshipped as a living god.