Liber Gemniagraphus sive Cleronomialis ecclesiæ Farfensis composed of 1324 documents, all very important for the history of Italian society in the 11th century. 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. Having collected all this detailed information, he set to work on a history of the monastery, the Chronicon Farfense; and when he was 70 years old, in order to facilitate reference to his earlier works, he compiled a sort of index which he styled "Liber Floriger Chartarum cenobii Farfensis". 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. All this wealth was a hindrance to the religious life once more. Between 1119 and 1125, Farfa was troubled by the rivalries between Abbot Guido, and the monk Berard who aimed at being abbot. During the Investiture conflict, Farfa was, more or less, on the side of the Ghibellines. The monks issued an Orthodoxa defensio imperialis in support of the Ghibelline party. The collection of canonical texts contained in the Regesto seems to omit purposely any mention of the canonical texts of the reforming popes of the eleventh century.s 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. At the end of the 14th century the Abbey of Farfa became a cardinalatial in commendam, and since 1842 the Cardinal Bishop of Sabina, a suburbicarian bishop, bears also the title of Abbot of Farfa. The Orsini family stayed to the early 16th century, consecrating the cathedral in 1494. They were succeeded by the Della Rovere, but the Orsini came back and stayed until 1542. Later the monastery was taken over by the Farnese family. 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. Under the management of Ranuccio's brother Cardinal Alessandro Farnese, the monastery joined the Cassinese Congregation (1567).