From the Prologue of Ochrid
Leo was born in Italy of pious parents. He was first archdeacon under Pope Sixtus III, and after his death was elevated, even against his own will, to the throne of the Pope of Rome. When Attila with the Huns came near Rome and was already preparing to destroy and burn this city, Leo went out before him in hierarchical vestments, tamed the anger of the Hun leader and averted the destruction of Rome. As much as Attila allowed himself to be counseled by the holy man, so much did he have to be frightened by a vision of the Apostles Peter and Paul, who stood beside Leo, and with fiery swords threatened Attila. And not only did Leo save Rome, but he helped greatly in saving Orthodoxy from the heresies of Eutyches and Dioscorus. This heresy consisted in merging the divine and human nature of Christ into one and, consequently, in denying two wills in the person of the Lord Savior. Because of this the Fourth Ecumenical Council was convened in Chalcedon, at which Leo's epistle was read, which Leo had written and laid on the grave of Saint Peter, and Saint Peter had corrected. Before death he spent forty days in fasting and prayer at the grave of the Apostle Peter, begging him to tell him whether his sins were forgiven. The Apostle appeared to him and said that all his sins were forgiven, except the sins in ordaining priests (from which it is seen how grave a sin it is to ordain the unworthy). The saint again fell to prayer until he was informed that even those sins had been blotted out. Then he peacefully gave up his soul to the Lord. Saint Leo reposed in the year 461.
