The presence of the monastic community dates back to Pope Gregory I, also known as the Great (590-604).
Pope Gregory II established a stable Benedictine community, which is still present here today.
In 936 Odon of Cluny reformed it: the abbot took the name of “abbas et rector Sancti Pauli”.
Hildebrand of Soana is the most illustrious monk among them, who, after having worked for the renewal of the Basilica and the life of its monastery, was elected Pope and took the name of Gregory VII (1073-1085). As Pope he initiated the reform of the Church, the so-called Gregorian reform.
The Abbey became the owner of a huge feudal patrimony.
From then on this complex passed through periods of great splendor but also dark ones as well, until the seizure of its goods in 1870. Nevertheless the monks, even at that time, did not abandon their charge by the tomb of the Apostle.
Even before the beginning of the 20th century, the monastic activity retrieved its vigor in a particular way by administering the Sacrament of Penance and promoting Christian Unity.
It was here on January 25, 1959 that Pope John XXIII announced the convocation of the Second Vatican Council.
The ancient Library contains more than 10,000 volumes which date back from between the 15th to the 17th century (including Maurist and Bollandist editions), while the modern one contains more than 100,000 books.