The Abbey of St. Gallen was the foremost centre for the study of the Etymologiae of Isidore of Seville in the Carolingian period. Not only can more than twenty early medieval manuscripts transmitting material from the Etymologiae be associated with Carolingian St. Gallen, but its scriptorium also produced two scholarly redactions of Isidore’s encyclopaedia in the second half of the ninth century. The prototype codices of these two redactions survive today in Swiss libraries, one as Zofingen, Stadtbibliothek, Pa 32, the other as St. Gallen, Stiftsbibliothek, MS 231 – 232. The first redaction represents an attempt to enrich the Etymologiae by incorporating Isidore’s De natura rerum into the encyclopaedia. The second redaction is the result of a collation of four sets of manuscripts of the Etymologiae, some of which survive today and bear collation marks and variant readings inserted into the margins. While none of the many hands that were involved in the collation and copying of the two redactions can be attributed to any of the known scholars active at St. Gallen in the ninth century, the redactions seem to have been produced over the course of several decades under the auspices of the praepositus and later abbot Hartmut.