(Nathan) In the mid-9th century, a group of Frankish bishops created one of the greatest forgeries in medieval history, making up an entire collection of fake letters and church law. Attributed to a Spanish author, "Isidore the Merchant," this canon law collection was cited and reused for almost 600 years before the forgery was discovered. In this episode, we'll uncover the motivations for this little-known forgery and how the authors managed to pull it off.