An 800-year-old map, the sole surviving copy of a chart used by the Roman Empire's courier service, was put on show for just one day.

The parchment scroll, nearly 7 metres (yards) long, could only be displayed briefly because too much light would damage it, before it was returned to storage at Austria's National Library, where it has been since 1738.

Named Tabula Peutingeriana after the German antiquarian who owned it in the 16th century, the map shows roads linking some 4,000 settlements as well as mountains, rivers and forests from Spain in the west to China in the east.

From north to south, the map covers the British Isles to north Africa.

The missing original, none are known to have survived, probably dated from the first half of the 5th centur, and so far only half of the 4,000 settlements have been identified.
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