For the rest, it comprises an oval map of the Old World, similar in type to Andrea Bianco's map of 1436. Its names, captions and geographic features, notably in eastern Asia, are apparently derived from the 'Tartar Relation', the manuscript with which the map is bound. This manuscript records the mission of Franciscan Friar John dc Piano Carpini to Tartary, 1245-1247. It constitutes a hitherto unknown account of Mongol history dictated by Carpini's companion, Friar Benedict the Pole, taken down and edited in 1247 by Friar C. de Bridia. This friar is otherwise unknown. Bridia has not been identified as a place name, and C. dc Bridia is a curious form of medieval personal name.

The map is drawn on two pieces of thin parchment mounted on a 'guard' which forms the fold whereas the 'Tartar Relation' is on paper which has been dated to about 1440 from the bulls' head watermark. The parchment has eight patched wormholes which do not match the wormholes of the 'Tartar Relation', a problem which was only resolved when a second manuscript, the 'Speculum Historiale' of Vincent de Beauvais, came to light.

The press announcement about the map was accompanied by the launch of a book, The Vinland Map and the Tartar Relation, which had been prepared in strict secrecy by the Yale University Press for publication on the same day. The book comprises an authoritative account of the manuscripts, commissioned by Yale University Library (who now owns the Vinland map) and written by R. A. Skelton, my predecessor as Superintendent of the Map Room of the British Museum (now Library), Thomas E. Marston, Manuscript Librarian at Yale University Library, and George Painter, Assistant Keeper in the Department of Printed Books of the British Museum. The manuscript was identified as a map and text copied about 1440 by an unknown scribe from lost earlier originals and inserted into a manuscript of Vincent de Beauvais' 'Speculum Historiale' (Mirror of History). In his 'Foreword', Alexander O. Victor of Yale, describes the documents as 'of dramatic novelty.' In The Geographical Magazine Skelton wrote that they were 'of so arresting a character as to prompt scepticism, if not incredulity.'[2]

Critics did indeed express varying degrees of scepticism and incredulity in the months which followed. The map has certain curious features apart from the delineation of Vinland. Its oval shape and northern orientation, for example, are unusual for a medieval map. The Latin of the captions and the nomenclature contain some errors: Iceland, for example, is named 'isolanda Ibernica'. Among the geographic features, the most remarkable (apart from Vinland) is the shape of Greenland, which is shown as an island. To most eyes its outline appears too good to be true. The Tartar Ocean in the Far East is not found (I believe) on any other map. The reviewer in the The Times Literary Supplement[3] characterised the maps as having, in a geographical sense, 'no ancestors, no close relations, and no descendants.' It was an unicum.

At the centre of the argument in the 1960s were two basic questions: was the map authentic and, if so, was it correctly dated to c. 1440? Was it really a pre-Columbian map of America? The manuscript containing the map and the 'Tartar Relation' was described by the dealer Laurence C. Witten of New Haven, Connecticut, who had purchased it 'as being from a private collection in Europe'. He declined to reveal the manuscript's provenance and the map has no known history before 1957.

As one of the few people who knows the history from the start I feel qualified to set out the facts as briefly as possible. I first saw the map and 'Tartar Relation' in 1957 when it was brought to the British Museum for comment by Enzo Ferrajoli, an Italian bookseller long resident in Barcelona. He was escorted by Joseph Irving Davis of Davis and Orioli, Hampstead. Ferrajoli also showed the map to booksellers in London, Paris, and Geneva. At Geneva in September of that year, in the office of Nicholas Rauch, Laurence Witten was told about the manuscript. He said later that he visited the owner, saw his library and bought the manuscript for US$3500, paying Ferrajoli a commission. On returning to the United States, Witten showed the volume to Marston and Vietor at Yale. Victor asked Witten to give Yale the first refusal should he decide to sell. Witten then withdrew the volume from his stock and gave it to his wife.

Witten was still investigating the authenticity of the manuscript when by chance Marston ordered (from a catalogue of Davis and Orioli Ltd) a fragment of Vincent de Beauvais' 'Speculum Historiale', offered at £75. He showed this to Witten, who made the remarkable discovery that the volume physically matched the Vinland map and the 'Tartar Relation,' and that the wormholes of the 'Speculum' matched those of the Vinland map. Thus, by what has been described as 'a process of mingled accident and deduction'[4] – some called it, more bluntly, a 'miraculous reunion'[5] – the 'Speculum' had arrived on the scene and helped to authenticate the map. The three documents had come from the same library where previously they had evidently been bound together in a different order. i.e. Vinland map, 'Speculum' and 'Tartar Relation.' An inscription on the recto of the first leaf of the map which reads (in translation) 'Delineation of the first part, the second part [and] the third part of the Speculum,' now made sense.

Marston gave the 'Speculum' to Mrs Witten, on the understanding that if she sold it, Yale would have the first refusal. In the Spring of 1959, Witten offered the manuscripts to Yale University Library which was unable to buy them. However, Victor and Marston referred Witten to an anonymous Yale benefactor who purchased them for a sum reported to be £100,000. 'Mr Witten, I think you got the greatest bargain in all the world,' the American librarian John Parker said to Witten in 1966. He answered, 'I thought so.'[6] The manuscripts passed into the custody of Yale and the anonymous benefactor entrusted Dr Skelton, Tom Marston and George Painter with the task of making a definitive study. Their book was in galley proof in 1965 when the benefactor donated the manuscripts to Yale University Library.

It was clear that the authors and the Yale authorities had done a great deal of work in private to satisfy themselves of the map's authenticity. Skelton said that at first he had taken on the role of devil's advocate, doubting the map's genuineness. Nevertheless, reviewing the conduct of the debate in the years from 1965 to 1970, and rereading The Vinland Map, it could be suggested that the authors asked their audience to accept the argument of the map's authenticity on trust since the map so far had not undergone a rigorous physical examination.

The map was subject to extensive public scrutiny in November 1966, when a number of experts from all over America, and a few from Europe, were invited to a symposium at the Smithsonian Institution in Washington DC, for face-to-face discussions with the principal persons involved.[7] The proceedings of this conference were not published until 1971.

Early in 1967 the manuscripts were brought to Europe to be exhibited in Scandinavia, the Netherlands, and London. At the British Museum the manuscript spent a few days at the Research Laboratory where A. D. Baynes-Cope and Dr A. E. Werner examined it by the use of simple optical methods such as ultraviolet light illumination and low-power binocular microscopy. Their investigation showed that the ink of the map was unlike any medieval ink known to them, and raised the first serious doubts about the map, a fact which found its way into the press.[8 ]The report was sent in due course to Yale, but remained confidential. Information about these doubts was not publicly revealed until February 1974, when Baynes-Cope contributed to a symposium held at the Royal Geographical Society.