The earliest atlases were not called by that name at the time of their publication. The first book that could be called an atlas was constructed from the calculations of Claudius Ptolemy, a geographer who worked in Alexandria circa A.D. 150. The first edition was published in Bologna in 1477 and was illustrated with a set of 27 maps, though scholars say that it is not known whether the printed maps were engraved versions of original maps made by Ptolemy, or whether they were constructed by medieval Greek scholars from Ptolemy's text.