(/ˈɪbən kælˈduːn/; Arabic: أبو زيد عبد الرحمن بن محمد بن خلدون الحضرمي, Abū Zayd ‘Abd ar-Raḥmān ibn Muḥammad ibn Khaldūn al-Ḥaḍramī; 27 May 1332 – 17 March 1406) was a leading Tunisian Arab historiographer and historian. He is widely considered as a forerunner of the modern disciplines of historiography, sociology, economics, and demography.
He is best known for his book, the Muqaddimah or Prolegomena (“Introduction”). The book influenced 17th-century Ottoman historians like Kâtip Çelebi, Ahmed Cevdet Pasha and Mustafa Naima, who used the theories in the book to analyze the growth and decline of the Ottoman Empire. 19th-century European scholars acknowledged the significance of the book and considered Ibn Khaldun to be one of the greatest philosophers of the Middle Ages.