St. Leo the Great

      St. Leo, aware of the greatness of the task which confronted him in the fifth century with the great upheaval caused everywhere in Europe by the invasion of the Barbarians, guided the destiny of the Church with such trust in God and wideness of view that he became not only the guardian of the faith but the saviour of western civilization. His encounter with Attila, "the scourge of God," has remained famous in history. His interventions in the doctrinal controversies of the time were no less important. It was at his instance that the Council of Chalcedon, in 451, defined the existence of the two natures, divine and human, in the one Person of Christ. He died in 461.

      Many of the Collects in the Missal were composed by St. Leo; they are among the most beautiful that we have. In the Breviary priests are well acquainted with the fine sermons of St. Leo for the great festivals of the liturgical year, in which the magnificence of the style matches the wealth and solidity of teaching.