The first pope who took the name Leo became pope in 440. Known as “Leo the Great,” the Roman aristocrat was a peacemaker who is most well-known for meeting Attila the Hun in 452 and successfully managing to dissuade him from invading Italy. He was also a doctor of the Church, promoted the doctrine of papal primacy (the authority of the pope over other bishops), and wrote 96 sermons that have been passed on to us today. A historic last (at least for now) was Pope Leo X (1513-1521). He was the last pope not to have been a priest at the time of his election to the papacy.
Pope Leo’s name also has a Marian significance. Pope Leo XIII wrote 11 encyclicals on the rosary and was also the first pope to embrace the concept of Mary as mediatrix, which holds that Mary helps distribute Christ’s grace through her intercession. One of the new pope’s first visits was to the Mother of Good Counsel in Italy, and when he was bishop of Chiclayo, Peru, he offered a prayer of consecration to the Blessed Virgin Mary before the pilgrim statue of Our Lady of Fátima, which he requested be brought to Chiclayo from the Fátima shrine in Portugal.