In 1138, a geographer from Ceuta arrived at the court of Roger II, the Norman King of Sicily. His name was Muhammad al-Idrisi. He was a descendant of the Prophet Muhammad through the Idrisid dynasty of Morocco, and he was about to create the most accurate map of the medieval world. He was also a Muslim working for a Christian king, which tells you something about 12th-century Sicily and something about al-Idrisi: both were more flexible than the century deserved.
Roger commissioned the project. He wanted a comprehensive map of the known world, and he was willing to pay for it. For fifteen years, al-Idrisi gathered existing maps, interviewed travellers, and sent expeditions to confirm reports. He drew on three centuries of Islamic cartography — a tradition unknown in Western Europe — as well as Ptolemy's Geography, translated into Arabic centuries before anyone in Paris could read Greek.
The result, completed in 1154, was the Tabula Rogeriana: a world map engraved on a silver disc six feet in diameter, weighing 450 pounds. A silver globe accompanied it. Alongside these was a book titled, with the modesty of an era that had not yet discovered understatement, "The Pleasure Excursion of One Who Is Eager to Traverse the Regions of the World." It contained 70 sectional maps and detailed descriptions of each region.
The map was oriented south-up, following Islamic convention. It showed Europe, Asia, and North Africa in detail — including the source of the Nile, which al-Idrisi placed in central Africa with an accuracy that European explorers would not match for another 700 years. The map was wrong about many things. It was more right than anything else available, which is the definition of the best map at any given moment.
Al-Idrisi's legacy is cartographic but also cultural: a Moroccan Muslim who worked for a Christian king, used Greek science preserved in Arabic, and produced a work that Europe relied on for three centuries. The silver disc was destroyed when the Normans lost Sicily. The book survived. The maps were copied, translated, and consulted by explorers who had never heard of Ceuta and could not have found it on a map — unless they were using al-Idrisi's.
Al-Idrisi drew the most accurate world map of the 12th century. The cities he mapped are still on the route.
Tell us about your trip →The Facts
- —Silver disc 6 feet diameter, 450 pounds
- —Completed 1154 after 15 years work
- —Earth circumference calculated: 23,000 miles (actual: 24,901)
- —70 sectional maps in accompanying book
- —Copied unchanged for 300 years
- —Arabic text printed Rome 1592
- —Silver disc melted down during 1160 palace intrigue
Sources
- Davis, Natalie Zemon. Trickster Travels: A Sixteenth-Century Muslim Between Worlds. Hill and Wang, 2006
- Tibbetts, Gerald. "The Beginnings of a Cartographic Tradition." In The History of Cartography, Vol. 2. University of Chicago Press
- Ahmad, S. Maqbul. "Cartography of al-Sharif al-Idrisi." In The History of Cartography, Vol. 2
