Scholars of the Islamic Golden Age

What the Islamic Golden Age was, and when

In 750 the Abbasid family overthrew the Umayyad caliphs, and in 762 the caliph al-Mansur founded a new round city at Baghdad on the Tigris. For the next five centuries, cities ruled by Muslim dynasties, from Córdoba in Spain to Cairo, Baghdad, Bukhara and Samarkand, were among the richest centres of learning in the world. The phrase “Golden Age” is a modern label, and historians increasingly avoid treating 1258 as a hard end: when the Mongols sacked Baghdad that year, killing the last Abbasid caliph in the city, science went on at new centres such as the observatory at Maragha in Iran (1259) and later Samarkand.

Four things made the age possible:

• A common language. Arabic became the language of government and scholarship across a huge empire, so a book written in Baghdad could be read in Córdoba.
• Paper. Papermaking reached Samarkand and Baghdad by the late 700s, making books far cheaper than parchment or papyrus.
• The translation movement. From the late 700s to the 900s, paid translators turned Greek works by Aristotle, Euclid, Ptolemy and Galen, along with Persian and Sanskrit texts, into Arabic. The best known, Hunayn ibn Ishaq, was a Nestorian Christian; many scholars of the age were Christians, Jews or Sabians.
• Patronage and practical need. Caliphs and courtiers paid for books and observatories, and religious life itself needed mathematics and astronomy: dividing inheritances under Islamic law, fixing prayer times and finding the direction of Mecca.

The House of Wisdom (Bayt al-Hikma) in Baghdad is often described as a great academy and university. The sources say less than that. Historians such as Dimitri Gutas argue it was mainly a palace library and archive that grew under Harun al-Rashid (ruled 786 to 809) and his son al-Ma'mun (ruled 813 to 833), and that most translation was funded by many patrons across the city, not one institution. It was real and important, but the grand image is partly modern.

Baghdad's mathematician: al-Khwarizmi

Muhammad ibn Musa al-Khwarizmi (about 780 to about 850) came from, or had family from, Khwarazm, south of the Aral Sea in modern Uzbekistan, and worked in Baghdad under al-Ma'mun. Almost nothing else is known about his life. Around 820 he wrote The Compendious Book on Calculation by Completion and Balancing; al-jabr, “completion” or “restoring”, gave us the word algebra. In its introduction he says the caliph encouraged him to write a short, useful book for inheritances, trade, lawsuits, land measurement and canal digging. He sorted equations into six types and solved them in words and with geometric diagrams; his best-known example, a square and ten roots equal to thirty-nine (x² + 10x = 39 in modern notation), is solved by literally completing a square, giving 3.

A second book, on calculating with Indian numerals, survives only in a Latin translation that begins Dixit Algorizmi, “al-Khwarizmi said”. From that Latin form of his name comes our word algorithm, and the book helped spread the decimal place-value system with zero, which Indian mathematicians had developed, into Europe. Robert of Chester translated the Algebra into Latin in 1145.

The physician-philosopher: Ibn Sina and his contemporaries

Ibn Sina (about 980 to 1037), known in Latin as Avicenna, was born near Bukhara in Central Asia. In his short autobiography he says he knew the Qur'an by heart at ten, read Aristotle's Metaphysics forty times without understanding it, and only grasped it after buying a cheap commentary by al-Farabi in a Bukhara bookshop. As a teenager he treated the Samanid ruler and was let into the royal library. He spent his adult life moving between courts in Iran as physician and sometimes vizier, writing about 1025 the Canon of Medicine, five books covering anatomy, diseases, drugs and treatment. Translated into Latin by Gerard of Cremona in the 1100s, it was a standard textbook in European universities into the 1600s. His Book of Healing covers logic, natural science, mathematics and metaphysics, and includes his “floating man” thought experiment: a person created in mid-air, unable to sense anything, would still know he exists, so the self is not the body.

He was one of many. The physician al-Razi (about 865 to 925) wrote the first clear account distinguishing smallpox from measles. Ibn al-Haytham (about 965 to 1040) in Cairo argued in his Book of Optics that we see because light enters the eye, and tested claims with controlled experiments. Al-Biruni (973 to about 1050), Ibn Sina's correspondent and sometimes rival, estimated the Earth's radius and wrote a long, careful study of India. In al-Andalus, Ibn Rushd (1126 to 1198), known in Europe as Averroes, wrote commentaries on Aristotle so influential that Latin scholars called him simply “the Commentator”. In 859 Fatima al-Fihri founded the mosque of al-Qarawiyyin in Fez, which grew into one of the oldest continuously operating places of learning in the world.

After the high point: Saladin, Mansa Musa, Ibn Battuta and Amir Khusrau

These four lived after the classic period, but they show how far Arabic and Persian learning had spread.

Saladin (1137 to 1193) was a Kurdish officer born in Tikrit who became ruler of Egypt in 1169, ended the Fatimid caliphate in 1171 and united Egypt and Syria. He destroyed the crusader army at Hattin on 4 July 1187 and took Jerusalem that October, letting most Christian inhabitants ransom themselves rather than massacring them. He fought Richard the Lionheart in the Third Crusade to a truce in 1192 and died in Damascus in 1193. He founded madrasas in Cairo, and the Jewish philosopher Maimonides worked as a physician at the court in Cairo during his rule. Our best source is the biography by his adviser Baha al-Din ibn Shaddad.

Mansa Musa (about 1280 to about 1337) ruled the Mali Empire in West Africa, the source of much of the gold traded across the Sahara. On his pilgrimage to Mecca in 1324 he passed through Cairo with so much gold that, according to the Cairo scholar al-Umari writing about twelve years later, its value there had still not recovered. He brought scholars and the architect Abu Ishaq al-Sahili home with him, and Timbuktu grew as a centre of Islamic learning. Modern claims that he was the richest person in history are guesses, not sourced figures.

Ibn Battuta (1304 to about 1369), a legal scholar from Tangier, travelled for nearly thirty years from 1325 and could find work as a judge from Delhi to the Maldives because the same Islamic legal training was valued everywhere. He visited Mali in 1352 and 1353, after Mansa Musa's death, and dictated his Rihla in 1355.

Amir Khusrau (1253 to 1325) was a Persian poet at the court of the Delhi sultans and a disciple of the Sufi master Nizamuddin Auliya. In his Nuh Sipihr (1318) he praised India's learning, languages and its invention of numerals and chess, which links him back to al-Khwarizmi's Indian numerals. Later traditions credit him with inventing qawwali and instruments such as the sitar; those claims are not supported by sources from his time.

Islamic Golden Age timeline

Big themes and debates

• Preservers or creators? Old textbooks said Arabic scholars “preserved” Greek learning for Europe. That undersells them: algebra, Ibn al-Haytham's optics, new trigonometry and hospital medicine were original work. Ask students to find one idea in this guide that no Greek author had.
• Islamic science or science in Islamic lands? Many key scholars were Christians, Jews or Zoroastrians writing in Arabic. Historians argue over which label describes the age better.
• Did it decline, and why? The old story blamed al-Ghazali's attack on the philosophers (1095) or the Mongols. Many historians now point out that astronomy and medicine flourished for centuries after, in Maragha, Samarkand, Istanbul and Delhi, and look instead at economics and printing, which reached the Ottoman world late.
• How knowledge travelled to Europe. Translators in Toledo and Sicily in the 1100s turned Arabic books into Latin. Students can trace one book, such as the Canon, from Iran to Montpellier.
• Myth and memory. The House of Wisdom, Saladin's chivalry and Mansa Musa's wealth have all been enlarged by later storytellers, European and Muslim. Check each claim against the earliest source.

Primary sources to read

• Al-Khwarizmi, The Algebra, introduction and the first worked problems (English translation by Frederic Rosen, 1831).
• Ibn Sina, his autobiography, continued by his student al-Juzjani (English edition: The Life of Ibn Sina, tr. W. E. Gohlman, 1974).
• Ibn Sina, the Canon of Medicine, Book 1, on the definition of medicine.
• Al-Razi, A Treatise on the Small-Pox and Measles (English translation by W. A. Greenhill, 1848).
• Baha al-Din ibn Shaddad, The Rare and Excellent History of Saladin (tr. D. S. Richards, 2001).
• Usama ibn Munqidh, The Book of Contemplation: a Syrian nobleman's memoir of life alongside the crusaders.
• Al-Umari, his description of Mali and Mansa Musa's visit to Cairo, in Corpus of Early Arabic Sources for West African History (ed. Levtzion and Hopkins, 1981).
• Ibn Battuta, the Rihla, chapters on Mali and Delhi.

If you are not sure how to read a translated source, our guide on how to analyze a primary source walks through it.

How to study the Islamic Golden Age: projects

• Solve it like al-Khwarizmi. Draw a square of side x and two rectangles of 5 by x for x² + 10x = 39, then fill in the missing corner to complete the square. Students see why the method is called completion.
• Trace a word. Algebra, algorithm, alcohol, zero, cipher, almanac and zenith all came into English through Arabic. Find each word's route and the scholar or trade behind it.
• One book's journey. Follow Ibn Sina's Canon from Hamadan to Toledo to a European university and make a map with dates.
• Two views of 1187. Compare Baha al-Din's account of Saladin's capture of Jerusalem with a Latin Christian account of the same event.
• Interview a scholar. Write questions about medicine and the mind for Ibn Sina and practise them by voice with Ibn Sina on Yuga. The recreation is built from his writings and the record, but it is not the man and can be wrong, and it will not give medical advice. Cite his autobiography and the Canon in your work.