Flavius Aetius died in 454.

Flavius Aetius was born in 396.

Aetius was his friend but they later dueled each other in the invasion of Gaul.

The Battle of the Catalaunian Plains (or Fields), also called the Battle of Châlons (also spelled Chalons or Chalon) or Battle of the Campus Mauriacus, took place in 451 between a coalition led by the Roman general Flavius Aetius and the Visigothic king Theodoric I on one side and the Huns and their allies commanded by Attila on the other. It was one of the last major military operations of the Western Roman Empire and marks the apex of the career of Flavius Aetius.

im sorry but im not sure but you could look it up on google I never hear this one, but if it is true it happened when Attila was young and lived in Rome under the hostage exchange program used in that time. Attila and Aetius had known each other since childhood when Attilla was a hostage of the Western Romans. Aetius also served as a hostage to the Huns and the Visigoths. After Atilla and his brother Bleda became kings of the Huns, Attila never met a Roman emperor to my knowledge.