This map is a reconstruction based on information found in the book Geographia, published by Claudius Ptolemy around 150 AD. In this book, Ptolemy introduced the concept of lines of latitude and longitude, using them to describe a multitude of places that could be reliably located on a map.
The original copies of Geographia had their own maps, but none have survived to the present day. The earliest known copies were made by Byzantine monks in the late 13th century, under the direction of Maximus Planudes. This particular copy was made by Byzantine monks in 1420.
On this map, after the map by Hecateus, more details can be seen. The outline of the Mediterranean Sea is almost perfectly drawn, with a close approximation also on the Atlantic coast of Europe, Egypt and the Middle East. The regions furthest from Egypt, Ptolemy's birthplace, have fewer correct details, as is the case with Africa and East Asia.
Sources
Español 
English (UK)