Attila the Hun,the scourge of God,was on a rampage. The most feared enemy of the Roman empire had plundered the Balkans,invaded France and conquered much of the Eastern empire when he crossed into Italy in 452. Attila wanted the sister of the Roman emperor as a trophy and he murdered and destroyed all that stood between him and Rome. His invasion was slowed due to lack of resources and diease,so the emperor saw an opportunity to perhaps buy some time by sending in the Pope to ask for mercy. Pope Leo rode into Attila’s camp unarmed(!)and got his meeting with the barbarian. No record of what was said,or offered,or begged,but when the meeting was over,Attila simply packed up and retreated home. What in the world did the Pope say?? It’s true that Attila’s forces were weakened,but he was an uncompromising monster that was hot for the emperor’s sister,with little in the way of taking her and Rome and he simply leaves with no excuses?? No wonder the Romans started calling Leo “The Great” afterwards.
Leo was a brilliant aristocrat that had influence over both secular and Church matters and he was a very powerful force against heresies. Monophysitism was an Eastern heresy that claimed Jesus had only one nature(divine),as opposed to the Church’s position that Jesus was fully divine and fully human. The Tome of Leo was a mic drop letter to all Eastern Bishops that had any doubts as to his position on the matter or to his authority over all Christians in the world. Basically what Leo said went. Pope Leo the Great is buried in St.Peter’s basilica and his feast day is November 10th.