Ibn Khaldun

Abd al-Rahman ibn Khaldun was a North African Arab historian, philosopher, judge and courtier of the fourteenth century. His Muqaddimah, the introduction to a universal history, set out a theory of how societies form, how dynasties rise and fall, and how economies work, and it is often described as a forerunner of sociology, economics and the modern philosophy of history. At its centre is the idea of asabiyya, the solidarity that binds a group together and carries it to power.

Ibn Khaldun was born in Tunis on 27 May 1332, into a family of Arab origin that had lived for centuries in Seville and had left al-Andalus for North Africa in the thirteenth century, as the Christian kingdoms advanced. The family had a long record of service to rulers, and Tunis was then the capital of the Hafsid dynasty. He received a thorough education in the Qur'an, Arabic, Maliki law, theology and the rational sciences, studying logic and philosophy with the scholar al-Abili. In 1348–1349 the Black Death reached Tunis and killed both his parents and many of his teachers, a disaster he later saw as one of the forces that weakened whole civilisations.

For more than twenty years Ibn Khaldun moved between the courts of North Africa and Spain, rising high and falling fast. In the early 1350s he entered the service of the Marinid sultan Abu Inan in Fez, in Morocco, but was imprisoned for nearly two years on suspicion of plotting. Released after the sultan's death in 1358, he held senior posts under his successor.

In 1364 he went to Granada, capital of the Emirate of Granada, the last Muslim state in Spain, where Sultan Muhammad V sent him on an embassy to Pedro the Cruel of Castile in Seville, the city of his ancestors. Pedro reportedly offered to return the family's old estates if he would stay, and he declined. Rivalry with the powerful vizier and writer Ibn al-Khatib made his position in Granada uncomfortable, and in 1365 he crossed to Bougie, in today's Algeria, where he became chief minister to a Hafsid prince. After the prince was killed in 1366, he served a succession of rulers in Tlemcen, Fez and elsewhere, often acting as a go-between with the Arab and Berber tribes of the interior.

In 1375, tired of politics, Ibn Khaldun withdrew with his family to Qal'at Ibn Salama, a castle in the hills of western Algeria, under the protection of a tribal chief. There, in about five months, he wrote the first draft of the Muqaddimah, the introduction and first book of his history. He later revised it for the rest of his life.

He began from a criticism of earlier historians, who in his view copied reports without asking whether they were possible. To test a report, he argued, a historian must understand the nature of human society, which he called umran, meaning civilisation or social organisation. History therefore needed a new science that studied the laws of social life, its environment, its economy and its institutions. He discussed how climate and food shape peoples, how crafts and trades develop in cities, how the division of labour creates wealth, why heavy taxes eventually reduce a state's revenue, and how the sciences flourish only where urban life is prosperous.

His best-known theory concerns asabiyya, often translated as group feeling or social cohesion. It is strongest among people living hard lives in the desert or mountains, where kinship and shared danger bind them closely. A group with strong asabiyya, especially when it is reinforced by a religious message, can conquer settled lands and found a dynasty, as the Arab conquerors and the Berber Almoravids and Almohads had done.

Once in power, however, the rulers adopt the comforts of city life. The ruler comes to rely on paid troops and officials rather than on his kinsmen, luxury grows, taxes rise, and the old solidarity fades. In Ibn Khaldun's view a dynasty typically lasts about three or four generations, roughly 120 years, before it becomes weak enough to be overthrown by a new group with fresh cohesion. The pattern fitted the history of North Africa that he knew so well, and it offered a general explanation of political change based on social causes rather than on chance or the virtues of individual rulers.

Ibn Khaldun finished a first version of his history, the Kitab al-Ibar, or Book of Lessons, in Tunis, where he lived from 1378. In 1382 he left on the pretext of making the pilgrimage and settled in Cairo, the capital of the Mamluk Sultanate and the greatest city of the Islamic world. The sultan Barquq appointed him a professor and, in 1384, chief judge of the Maliki school. He was known as a strict and incorruptible judge, which made enemies, and he was appointed and dismissed six times over the following two decades. In 1384 his wife and children, sailing from Tunis to join him, were drowned in a shipwreck off Alexandria.

In 1400–1401 he accompanied the Mamluk army to Damascus, which was besieged by Tamerlane. According to his own account, he was lowered from the city walls by rope and spent several weeks in the conqueror's camp, where Timur questioned him at length about North Africa. He returned to Cairo, completed his autobiography and continued teaching until his death on 17 March 1406.

Ibn Khaldun had some admirers among Mamluk and later Ottoman scholars, but no school followed his method. European orientalists rediscovered him in the nineteenth century, and the British historian Arnold Toynbee called the Muqaddimah perhaps the greatest work of its kind ever created. Modern writers have compared him with Machiavelli, Vico and Montesquieu, and his ideas on taxation and labour are often cited by economists. Historians warn against making him simply a modern social scientist born too early, since he wrote as a Muslim jurist who believed in divine law, and he was sharply critical of philosophers' claims to certain knowledge of metaphysics.

He belongs both to the history of Islamic and Jewish philosophy and to the history of history-writing, and is a national figure in Tunisia, where his portrait appeared on banknotes and his statue stands in the centre of Tunis.