IDRĪSĪ, AL-(1100–C. 1165). Al-Idrīsī was a celebrated Islamic geographer, cartographer, royal adviser to the Norman king of Sicily *Roger II (r. 1130–1154), and author of one of the greatest geographic works of the medieval world.
Few facts are known about al-Idrīsī’s life. A noble by birth, al-Idrīsī traced his lineage through a long line of important figures to the Prophet *Muhammad. A member of the Hammudid dynasty, he was born in Sabtah, modern Ceuta in Morocco, and spent much of his early life traveling in North Africa and Spain. Al-Idrīsī studied in Cordova for a number of years, and his travels took him to many parts of western Europe, including Portugal, northern Spain, the French Atlantic coast, southern England, and Asia Minor. In 1145, al-Idrīsī entered the service of King Roger II and spent the remainder of his life at Palermo. There is little scholarly agreement on al-Idrīsī’s reasons for going to Sicily, and Muslim biographers seem to have taken little interest in him or his work, possibly because he was employed by a Christian king and thus would have been considered as something of a renegade. One fourteenth-century source informs us that he was invited by Roger to come to Palermo in order to make a map of the world for him. It is certain that Roger paid him handsomely for his services.
Although he had traveled extensively, it was not until al-Idrīsī came to Sicily that he established himself as a geographer and cartographer. During his career at Roger II’s court, al-Idrīsī was responsible for the production of three important geographical works. The first of these, now lost, was a silver planisphere depicting a map of the world on one side and the zodiac and the constellations on the other. It is described as having been nearly six feet in diameter and weighing more than 450 pounds. The second was a series of world maps, on the Ptolemaic model, which divided the Earth north of the equator into seven climatic zones of equal width, each of which was further subdivided into ten portions by lines of longitude. These maps, a major feat in and of themselves, provided information more accurate on many areas than any maps produced