Medieval Islamic geography was based on Hellenistic geography and reached its apex with Muhammad al-Idrisi in the 12th century.
After its beginnings in the 8th century based on Hellenistic geography, Islamic geography was patronized by the Abbasid caliphs of Baghdad. Various Islamic scholars contributed to its development, and the most notable include Al-Khwārizmī, Abū Zayd al-Balkhī (founder of the "Balkhi school"), and Abu Rayhan Biruni. : )
Islamic cartographers inherited Ptolemy's Almagest and Geography in the 9th century. These works stimulated an interest in geography (particularly gazetteers) but were not slavishly followed. Instead, Arabian and Persian cartography followed Al-Khwārizmī in adopting a rectangular projection, shifting Ptolemy's Prime Meridian several degrees eastward, and modifying many of Ptolemy's geographical coördinates.
Having received Greek writings directly and without Latin intermediation, Arabian and Persian geographers made no use of European-style T-O maps.
Muslim scientists made many of their own contributions to geography and the earth sciences. In the 11th century, the Karakhanid Turkic scholar Mahmud al-Kashgari was the first to draw a unique Islamic world map, where he illuminated the cities and places of the Turkic peoples of Central and Inner Asia. He showed the lake Issyk-Kul (in nowadays Kyrgyzstan) as the center of the world.