This terrestrial globe reproduces a world map which was drawn at the instance of the Abbasid Caliph al-Ma’mūn by a group of scholars in the first quarter of the ninth century AD. The scholars based their map on the image of the world as known to their Greek predecessors, but they improved and extended the image considerably, and depicted it upon a grid with the help of longitudes and latitudes, which they had determined mostly by astronomical-mathematical procedures. This world map was lost and was rediscovered in 1987 in a manuscript in Topkapı Saray. It had a profound influence – directly or indirectly – on the cartographic image of the world in the Islamic world as well as in Europe.