in French "How can we understand the influence of an empire spanning nine centuries, encompassing successive dynasties and numerous caliphates, the emblematic centres of which were Constantinople, Baghdad and Cordoba? successive dynasties and numerous caliphates, the emblematic centres of which were Constantinople, Baghdad and Cordoba? How can we understand what made up civilisation and religion within this empire? Gabriel Martinez-Gros, in collaboration with Frmeaux - Grande Mosque de Paris, presents an overview of the history of this great civilisation, covering nine centuries of Arab conquests and highlighting the Byzantine and Persian empires. It explores the succession of dynasties such as the Umayyads and Abbasids, as well as the opening up to Persian and Greek cultural influences, the apogee of the empire in the year 1000, the Crusades, Genghis Khan, intellectual exchanges with the West, and the 16th century through the Ottoman Empire. Based on the theories of the medieval historian Ibn Khaldun, the author analyses the birth, apogee and decline of this empire, which left a considerable and remarkable legacy in the scientific, philosophical, artistic and literary fields. Book, in French. Claude COLOMBINI et Patrick FRMEAUX"