The
Ptolemy world map is a map of the
world known to Hellenistic society in the 2nd century. It is based on the description contained in
Ptolemy's book
Geography, written . Based on an inscription in several of the earliest surviving manuscripts, it is traditionally credited to
Agathodaemon of Alexandria. Perhaps the most significant contributions of Ptolemy's maps are the first uses of longitudinal and latitudinal lines as well as specifying terrestrial locations by celestial observations. The
Geography was translated from
Greek into
Arabic in the 9th century and played a role in the work of
al-Khwarizmi before
lapsing into obscurity. The idea of a global coordinate system revolutionized European geographical thought, however, and inspired more mathematical treatment of cartography.