Abstract Biomolecular analysis of historical parchment legal documents is providing new insight into their production and use. Successful interpretation of this data is dependent on understanding if the location and date written on the document accurately reflect where the animal from which the parchment was produced was raised and when it died. Our analysis reveals that the location the deed concerns, or that of the stationer through whom it was sold, typically bears no relation to the animal’s origin, but that the date the agreement was signed was probably only a few months after the animal’s death.