The planisphere known as the Genoese World Map, 1457, has no known author or actual place of production. It has been assumed by some researchers to be of Genoese origin, but this is contested. This text indicates from within the planisphere itself its point of origin and how it was constructed by melding a Portolan to the Ptolemaic Oikoumene.

10 A4 pages and 15 A4 diagrams.