Ibn Khaldun
North African historian, sociologist and statesman (1332–1406), born in Tunis into an aristocratic Andalusi family that had emigrated following the Reconquista, and one of the most original minds in medieval intellectual history. He received a thorough classical education in Islamic law, theology and Arabic literature before leading a turbulent life as an official, diplomat and courtier among the sultanates of the Maghreb, Granada and Egypt, often entangled in political intrigues that landed him in prison at least once and repeatedly forced him to change masters and allegiances; the most celebrated episode of his life was his meeting with Tamerlane during the siege of Damascus in 1401, where, lowered by ropes from the city wall, he negotiated the city's safety and left a detailed account of their conversation. His masterwork, the Muqaddimah ('Introduction', 1377), originally conceived as a prologue to a great universal history titled Kitab al-Ibar, became an autonomous and revolutionary treatise on the principles of human society: in it he developed the concept of asabiyyah, the group cohesion and solidarity that explains the rise and fall of dynasties and civilisations in generational cycles of roughly three generations, analysed the transition from nomadic, Bedouin life to sedentary, urban life and its political, economic and moral consequences, and anticipated ideas in economics (labour theory of value, population and production curves) and sociology that the West would not rediscover for centuries. Often rightly regarded as the founder of sociology and the philosophy of history as empirical disciplines, his actual influence on later Islamic thought was fairly modest until the West 'rediscovered' him in the nineteenth century, after which thinkers such as Arnold Toynbee have praised him as one of the greatest historians of all time.