In the Carolingian period, most intellectual centers owned a copy of the Etymologiae of Isidore of Seville. Large and important centers, such as Reims or Fleury, may have possessed as many as three or four copies. The ultimate record-holder is, however, St Gallen. By the end of the ninth century, the St Gallen library held at least five complete series of the Etymologiae and a few more collections containing excerpts from Isidore’s monumental encyclopedia. Moreover, several manuscripts, which are now no longer preserved at St Gallen, contain traces that suggest that they were owned by the monastery in the second half of the ninth century. To what should this interest in the Etymologiae at St Gallen be attributed? Is there a deeper significance in the fact that many of the codices of the Etymologiae from Carolingian St Gallen represent distinct text-versions, some of them rare in the Carolingian area, so that the abbey possessed not only one of the largest but also most diverse collections of Isidore’s encyclopedia? And is there perhaps a connection between this extraordinary amassing of manuscripts at St Gallen and the traces of one, or perhaps even two, large-scale scholarly projects concerning Isidore’s Etymologiae found in the same codices?