Al-Idrisi
Muhammad al-Idrisi was the foremost geographer and cartographer of the medieval world. Working at the court of King Roger II of Sicily, he spent fifteen years creating the Tabula Rogeriana, a comprehensive description of the world accompanied by seventy detailed sectional maps. This atlas, completed in 1154, remained the most accurate map of the world for the next three hundred years. Al-Idrisi incorporated data from Greek, Roman, Islamic, and his own original sources, synthesizing information from travelers and merchants across the known world. He accurately depicted the sources of the Nile River, described the shape of many coastlines, and included details about climate, resources, and populations. His accompanying geographic text, Nuzhat al-Mushtaq (Entertainment for He Who Longs to Travel the World), is a masterwork of medieval geography.