Claudius Ptolemy was a Greek scholar who lived in about 150 AD. Utilising the resources of the great library of Alexandria in Egypt he compiled a description of the world based on the writings of Greek astronomers, mathematicians and geographical writers of earlier centuries. The resulting book, the Geographia (also known as the Cosmographia) contained instructions on how to construct maps using projections to 'flatten' the image of the Earth and co-ordinates to place geographical features and towns. It is not known whether he actually drew any maps. The book never seems to have been well known in the western Roman empire and its text was completely lost following the Empire's fall in the late fifth century. There was some, but not much, knowledge of it in the eastern Empire. This map, one of the earliest Ptolemaic maps known, comes from a copy of the Geographia that was created in the Byzantine Empire in about 1300. It is copied from a map by the monk Maximos Planudes (1260-1310) commissioned by the Emperor Andronicus II Palaeologus. The bulk of the atlas from which it comes is still in Vatopedi Monastery on Mount Athos. It looks very different from the form of the British Isles to be found on medieval world maps, on sea charts and on home-grown maps. The strange sharp rightward turn of Scotland is to be found on all Ptolemaic maps.