Because evidence concerning the Viking discovery of North America in the tenth and eleventh centuries is so incomplete, investigation of this area of history will be substantially aided by the discovery of new documents. Such as the claim made for the previously unknown manuscripts here published for the first time. They are two documents copied about 1440 from much earlier originals, now lost. The first is an account of Friar John of Plano Carpini's mission to the Mongols in 1245-47. The second is a world map, including the western ocean, with delineations of Iceland, Greenland, and a land mass named Vinland which represents the North American mainland as known to the medieval Norsemen.