At the heart of the Abbey Library of St. Gall is the unique collection of manuscripts. Not only is the number of manuscripts truly impressive, but the collection is unusually uniform and complete. From these manuscripts, modern scholars can reconstruct the spiritual and cultural life of the abbey from the Early Middle Ages until 1805 (dissolution of the abbey). Further insights into life at the abbey can be obtained from the remarkably complete collection of documents and deeds stored in the Abbey archives.
The first indications that the Abbey of St. Gall was producing its own manuscripts date from the middle of the 8th century, at the time of the founder, Abbot Otmar (who ruled from 719 to 759), and his successor Johannes (who ruled from 759 to 782). From the 8th until the 11th century, the Benedictine Abbey of St. Gall was one of Europe's leading centres of culture. A number of the abbey's creative monks made important contributions to the cultural history of Europe. For example, Wolfcoz, Folchart and Sintram were well-known illuminators of manuscripts. Then there were illustrious poets and musicians such as Ratpert, Tuotilo, Notker the Stammerer and the Ekkeharts, not to mention Notker the German, who was a master of the Old High German Language.
Today, the manuscripts are accessible to researchers. Some of them can be viewed by the general public during the annual thematic exhibitions in the Baroque hall.
The over 2100 manuscripts are classified according to subject. The numbering system is also based on this principle. However, the weak point of this system becomes apparent when classifying the more recently acquired manuscripts. From Codex 1094 onwards, these manuscripts could unfortunately no longer be classified according to subject in-between the older works.
| Manuscript Nos. |
| 1 - 84 | Biblical manuscripts |
| 85 - 337 | Church Fathers and ecclesiastical writers |
| 337b - 546 | Liturgical manuscripts and devotional books |
| 547 - 669 | Lives of saints, secular history, geography |
| 670 - 749 | Canon law, Roman and Germanic law |
| 750 - 762 | Medicine |
| 763 - 815 | Dogmatic and ascetic literature |
| 816 - 849 | Philosophy and mathematics |
| 850 - 913 | Roman classics, scholia and grammar books, Latin and German dictionaries and literature |
| 914 - 925 | Monastic rules |
| 936 - 1014 | Ascetics |
| 1015 - 1081 | Sermons, devotional literature |
| 1082 - 1093 | Antiquity, books on heraldry |
| 1094 - 1725 | Books dating from the 15th to the 18th century, not classified according to subject |
| 1716 - 1984 | Additional collection; acquired 1875-1980 |
| 1985 - 2092 | Mainly prayer books and devotional literature dating from the 18th and 19th centuries |
| 2093 - 2112 | Miscellaneous; acquisitions and donations |