According to the tradition, after being named bishop, he became enamoured of the monastic life, and chose a forested hill near the Farfa stream, a tributary of the Tiber, to build a church and a monastery.

The foundation the Abbey of Saint Columbanus in Bobbio and of Farfa by monks from Gaul, about 681, heralded a revival of the great Benedictine tradition in Italy.

The Constructio Monasterii Farfensis, which dates probably from 857, relates at length the story of its principal founder Thomas of Maurienne;[6] he had made a pilgrimage to Jerusalem and spent three years there.

While in prayer before the Holy Sepulchre, the Virgin Mary in a vision warned him to return to Italy, and restore Farfa; and the Duke of Spoleto.

At a very early date traces of this legend appear in connexion with the foundation by three nobles from Benevento of the monastery of St Vincent on the Volturno, over which Farfa claimed jurisdiction.

The Lombard chiefs, and later the Carolingians, succeeded in withdrawing Farfa from obedience to the Bishops of Rieti, and in securing many immunities and privileges for the monastery.

According to the Chronicon Farfense, with the exception of the Abbey of Nonatola, Farfa was at this period the most important monastery in Italy both from the point of view of worldly riches and ecclesiastical dignity.

Owing to the protection of the Emperor Otto I, the abbot John III, who had been consecrated circa 967 by the pope, succeeded in re-establishing a semblance of order.

In 1103, Gregory wrote the Largitorium, or Liber Notarius sive emphiteuticus, a lengthy list of all the concessions, or grants, made by the monastery to its tenants.

Gregory was a man of real learning, remarkable in that, as early as the eleventh century, he wrote history with accuracy of view-point, and a great wealth of information.

The monks of Farfa owned 683 churches or convents; two towns, Centumcellæ (Civitavecchia) and Alatri; 132 castles; 16 strongholds; 7 seaports; 8 salt mines; 14 villages; 82 mills; 315 hamlets.

But when, in 1262, the victory of the popes over the last of the Hohenstaufen put an end to the Germanic rule in Italy, Farfa sought the protection of Urban IV.

Ranuccio Farnese (cardinal) was its abbot commendatory when in 1561 he commissioned the Flemish painter Hendrick van den Broeck to create a large painting of the Last Judgememt for the Abbey.