The Cross-Religious Scholarly Court of Sicily
Sicily under Norman rule was a rare cultural melting pot in the medieval Mediterranean world where Christian, Islamic, and Jewish scholars were active together in exchange; King Roger II himself, though a devout Christian, held a keen interest in Islamic scholarship and culture, and specially invited al-Idrisi to direct the vast project of compiling and drawing the world map — this scholarly cooperation across the barriers of religion was especially remarkable amid the fierce religious antagonism of the time.
The Tabula Rogeriana
The world map al-Idrisi completed over fifteen years was called the "Tabula Rogeriana" (meaning "the Map of Roger," in honor of his patron Roger II), engraved on a huge silver disk, the map drawn in the then-rare "south-up, north-down" manner, marking in detail the mountains, rivers, cities, settlements, and trade routes of the three continents of Eurasia and Africa, the peak of medieval geographical achievement; regrettably the precious original silver disk was later melted down in the political turmoil of Sicily, but the surviving paper copies let this precious geographical heritage pass down to later ages.