 Its compiler was an anonymous Mozarab (Christian) chronicler, living under Arab rule in some part of the Iberian peninsula.Since the 16th century, it has been attributed to an otherwise unknown bishop, Isidorus Pacensis but this attribution is now widely accepted as being the result of compounded errors.Henry Wace explained the origin and the phantom history of "Isidorus Pacensis", an otherwise unattested bishop of Pax Julia (modern Beja, Portugal).