Leo the Great, a native of Tuscany, was elected bishop of Rome in 440 and is perhaps best known for meeting with Attila the Hun in 452 and persuading him to turn back from his invasion of Italy.  The nearly 100 sermons and 150 letters of his that have survived are mostly concerned with theological questions concerning the person of Jesus Christ and his role as Mediator and Saviour.  Leo taught extensively on Christ's presence in the Church: in the teaching of Scripture, in the preaching of the faith, in the liturgy and in the life of the individual believer.

Concerning the content of Christ's teaching, his own sacred words bear witness; thus whoever longs to attain eternal blessedness can now recognize the steps that lead to that high happiness.