The Book of Roger: a treasure of medieval cartography by Al-Idrissi
In the 12th century, at a time when the world was still largely unexplored and unknown, a scholar named Al-Idrissi produced an exceptional work that would mark the history of geography and cartography: the Book of Roger. Commissioned by the Norman King Roger II of Sicily, this work represents a unique synthesis of the geographical knowledge of the time, compiled from travelers' accounts, scientific observations, and ancient traditions. In this article, we delve into the fascinating story of Al-Idrissi, the creation of this major work, and the details of the world map it contains.
Al-Idrissi: The Scholar Behind the Book of Roger
Abu Abdallah Muhammad ibn Muhammad ibn Abdallah ibn Idriss al-Qurtubi al-Hassani, better known as Al-Idrissi, was one of the greatest geographers of the Middle Ages. Born in 1100 in Ceuta, on the North African coast, he descended from a noble family with ties to Idris I, great-grandson of Muhammad. His education was marked by studies in Córdoba, the intellectual and cultural center of the Almoravid Empire, where he trained in science, geography and cartography.
Al-Idrissi traveled throughout Europe, the Maghreb, and the Mediterranean regions, enriching his knowledge through his own observations and the accounts of the merchants and navigators he met. In 1139, he settled in Palermo, Sicily, at the court of King Roger II. There, he was invited to compile his knowledge in a work that would be both scientific and artistic: the Book of Roger. For twenty years, he worked tirelessly to collect data and produce what would become a major reference in the history of cartography.
The Book of Roger: A Royal Commission from Al-Idrissi
The Book of Roger, or Kitāb nuzhat al-mushtāq fī ikhtirāq al-āfāq , is a monumental work produced by Al-Idrissi at the request of Roger II, King of Sicily. This enlightened sovereign, passionate about knowledge, wanted an exhaustive and precise representation of the known world, at a time when geographical information was still fragmentary and often inaccurate.
The World Map of Roger's Book by Al-Idrissi
Completed in 1154, the Book of Roger combines a planisphere engraved on a silver disk with a text describing in detail the regions mapped. The work is divided into seven climatic zones, according to Ptolemy's model, and each zone is subdivided into longitudinal sections. Al-Idrissi describes the physical conditions, cultures, and infrastructure of the regions represented, demonstrating an astonishing precision for the time.
To gather his information, Al-Idrissi relied on travelers' accounts and written sources. Informants from different parts of Europe, Africa and the Middle East also contributed to his work. This unique collaboration produced a remarkably detailed document, combining Arab, Byzantine and Western scientific traditions.
The World Map in the Book of Roger by Al-Idrissi
The world map included in the Book of Roger, oriented with south at the top, is one of the most accurate of the Middle Ages. It depicts the continents of Eurasia and Africa and is full of fascinating details about the regions of the known world at the time.
Brittany
Al-Idrissi devotes particular attention to Brittany, which he describes with great precision. He mentions thirteen cities, including Léon (now Douarnenez), Saint-Mathieu, Saint-Malo, Dinan and Vannes. Although the Armorican peninsula is slightly exaggerated in its proportions, its outlines show an advanced geographical knowledge.
The sources of the Nile
Drawing on Ptolemy's theories, Al-Idrissi places the sources of the Nile in mythical mountains fed by eternal snows. He also describes the tributaries joining to form the great river that crosses Africa and flows into the Mediterranean.
The Indian Ocean
Al-Idrissi illustrates the Indian Ocean with details that reflect the tales of sailors. He depicts India in a distinctive triangular shape, including Sri Lanka, then called "Taprobane".
The hypothetical southern continent
In the absence of precise information on the lands located south of the equator, Al-Idrissi imagines a hypothetical southern continent. This addition demonstrates the desire to complete the map with a balanced, if speculative, vision.
Sicily
Al-Idrissi gives a central place to Sicily, the meeting point of Western, Byzantine and Muslim cultures. The description of the island illustrates its geopolitical and economic importance, particularly during the reign of Roger II.
Conclusion
The Book of Roger and the map made by Al-Idrissi are exceptional testimonies of the geographical and cultural knowledge of the 12th century. By combining empirical data, historical accounts and artistic vision, Al-Idrissi produced a timeless work that continues to fascinate. This masterpiece of medieval cartography offers us a unique window on the perception of the world at the time, testifying to the legacy of a visionary geographer and the intellectual dynamism of the Sicilian court. An invitation to explore the world with the eyes of another time.
