Since its publication in 1981, this book has established itself as the major new interpretation of the historical concept of Ibn Khaldûn, the great figure of Arab-Islamic letters and of historical thought overall--a figure generally thought to be on a par with Thucydides, Vico, Herder and others of similar stature. The author has eschewed the ahistorical interpretations to which Ibn Khaldûn has normally been subjected, both by authors who have sought unduly to modernise his thought, and by those who sought to freeze it in stereotypical models of Islamic philosophy. Ibn Khaldûn is not only a true historical source of his time; he is also taken as the unchallenged sociological and cultural interpreter of medieval North Africa and much of medieval and modern Arab-Islamic culture as well. The validity of his discourse is considered to be so universal as to confer upon his ideas the status of progenitor--or, at least, anticipator--of a great variety of modern ideas.