June 12: Pope Leo III
Founder of the Palatine School
Pope Leo III, born in Rome, was educated from childhood within the vestiarium of the Roman Church, the office that managed the papal treasury.
Ordained as a subdeacon and later as Cardinal with the titular church of Santa Susanna, he maintained an important role in that administration which he officially headed in 789, becoming one of the main collaborators of Pope Adrian I.
He was elected Pope on the very day of Adrian’s funeral, December 26, 795. Upon his election, he sent to Charlemagne, King of the Franks, the keys of the Confession of Saint Peter and the banner of the city of Rome as a sign of respect and homage. He also invited the king to send his representatives to Rome. Charlemagne, already during Adrian I’s pontificate, had played a crucial role in strengthening the temporal power of the Papacy and continued to act as a protector and overseer of Rome. This authority was officially recognized by the title "Patrician of the Romans," granted to him directly by the Popes.
In 798 Pope Leo III bestowed the archiepiscopal pallium on Arno, Bishop of Salzburg thereby establishing the ecclesiastical province of Bavaria. This decision was in line with the wishes of Charlemagne and the Bavarian bishops, aimed at improving the religious organization of the region and reinforcing its ties with the Apostolic See.
The Pope also intermediated in matters concerning the Church in England, confirming the primacy of the Diocese of Canterbury and sending the pallium to the Archbishop of York.
During his pontificate, Leo III had to confront the issue of Adoptionism, a doctrine mainly promoted by two Spanish bishops, Felix of Urgell and Elipandus of Toledo, which held that Jesus as a man was not the Son of God by nature but only by adoption. This position was deemed heretical by the Church.
On Christmas Day in the year 800, Leo III crowned Charlemagne as “august emperor”.
Among the Pope’s most significant achievements was the foundation of the Palatine School, a cultural institution that marked the first step toward the future establishment of the University of Paris.
Pope Leo III died on June 12, 816, and was buried in St. Peter’s Basilica.