Q. This week we celebrate the Memorial of Pope St. Leo the Great (November 10). How many saints have the title “the Great,” and how is that title assigned?
A. Three saints who were popes customarily carry the title “the Great”: Pope Leo I (reigned 440-461), Pope Gregory I (590-604), and Pope Nicholas (858-67). The Church has never officially granted the title “Great” to any of these saints; they have been designated such by popular acclamation at the time of their deaths and by the witness of subsequent history.
Pope St. Leo the Great earned that title by his tireless preaching against the multiple powerful heretical movements of his day. He convoked the Council of Chalcedon (451), where his famous Tome defending the truth about the Incarnation of the Son of God was enthusiastically embraced by the Council Fathers as “the faith of the Apostles.” The Council went on to define the matter dogmatically so that the Church could have certainty about it in the face of so much confusion spread by the heretical teachers of the day.
Leo was also great as a leader with regard to Church reforms, missionary efforts, and his defense of the city of Rome. In 452 he personally went out to meet Atila the Hun, the barbarian invader known as “the Scourge of God,” and persuaded him not to sack the imperial capital. For this reason, Leo was dubbed “the Shield of God.”
We should add that one more saint who was not a pope has traditionally been called “the Great”: St. Gertrude the Great (1256-1301). She was a Cistercian nun whose remarkable scriptural, theological, philosophical, and literary learning, along with many profound mystical experiences, earned her that title.