The exact place and date of his birth is unknown. The earliest certain historical information available about Saint Leo shows him to have been a Deacon of the Catholic Church during the years 422 to 432.
Upon the death of Pope Sixtus III, Leo was chosen as his successor. He was consecrated Pope in Rome on September 29, 440.
Leo's primary interest was in maintaining the unity of the Church. He taught against certain heresies and organized the Church setup so that the Pope, the Bishop of Rome was recognized as the head of the Church.
Leo is famous for meeting with Attila, the Hun and preventing a march on Rome after the Huns had devastated Northern Italy.
Leo the Great was also renowned for building and restoring Churches. He built a basilica over the grave of Pope Cornelius in Via Appia, replaced the roof of Saint Paul's without the walls and restored Saint Peter's on the Vatican.
This great leader was also known for the spiritual leadership he provided for the Roman congregations. His sermons, of which 96 have been preserved, are considered remarkable for their depth, clarity and style. A total of 143 letters written by Leo are still preserved and there are also 30, which were sent to him.
Saint Leo the Great died on November 10, 461. His remains are buried in Saint Peter's with a special altar over them.
In 1754, Pope Benedict XIV proclaimed Leo a Doctor of the Church. His Feast Day is November 10th.