Intrepid readers, your crash course continues. In this installment: the biggest event in the last century of that hopping, happening field of Pseudo-Isidore Studies.
About ten years ago, Klaus Zechiel-Eckes discovered that our forgers likely did their work at the monastery of Corbie. He found two Corbie manuscripts -- St. Petersburg, National Library of Russia, Ms. F. v. I. 11, and Paris, BNF, Ms. lat. 11611 -- with curious marks and letters in the margins. Both manuscripts contain texts that Pseudo-Isidore used as sources -- The Petersburg codex has the Historia Tripartita of Cassiodorus; the Paris book has the acts of the Council of Chalcedon. In both cases, the marginal notes mark off passages that later on appear as part of that mosiac of sources constituting Pseudo-Isidore's forged decretals, and also the forged capitulary collection of Benedictus Levita.
So it looks like a secretarial team was going through manuscripts of key works in the Corbie library (one of the best appointed in all of Carolingian Europe), highlighting relevant passages. Later on, somebody else took all of these highlighted excerpts and stitched them together, yielding the forgeries as we have them today. So far we only know of several manuscripts with the source marks. If this was how Pseudo-Isidore did all of his research, though, poking about should yield some more.
Zechiel-Eckes argues that the forgery team was likely headed by Paschasius Radbertus, abbot of Corbie at the time. He also argues that it was done in the later 830s -- significant because scholars before Zechiel-Eckes wanted to stick the forgeries much later, in the 840s. His arguments on this front are not quite as airtight, and in some ways they hark back to the earlier ideas of a nineteenth-century scholar named Wasserschleben.
So, setting Paschasius Radbertus and the 830s aside for the moment -- what are the implications of Corbie? Well it's in the archiepiscopal province of Reims, long thought to be the Pseudo-Isidore's center of operations. And Zechiel-Eckes's discovery ties in with other evidence associating Pseudo-Isidore with Corbie as well. So none of this is entirely unexpected, though it is nevertheless odd to find a forgery primarily about the status and privilege of bishops coming out of a monastic center.
While we certainly have to reckon with the Corbie library as Pseudo-Isidore's workshop, the staff of that workshop remains mysterious.