Flavius Aetius was a Roman general and statesman of the closing period of the Western Roman Empire. He was a military commander and the most influential man in the Empire for two decades (433–454). He managed policy in regard to the attacks of barbarian federates settled throughout the West. Notably, he mustered a large Roman and allied (foederati) army in the Battle of the Catalaunian Plains, ending an invasion of Gaul by Attila in 451, though the Hun and his subjugated allies still managed to invade Italy the following year, an incursion best remembered for the Sack of Aquileia and the intercession of Pope Leo I. In 454, he was assassinated by the emperor Valentinian III.
Aetius has often been called the "Last of the Romans". Edward Gibbon refers to him as "the man universally celebrated as the terror of Barbarians and the support of the Republic" for his victory at the Catalaunian Plains. J. B. Bury notes, "That he was the one prop and stay of the Western Empire during his life time was the unanimous verdict of his contemporaries."