Thinkers Timeline

Jabir ibn Hayyan (c.721-815 CE), known in medieval Europe as Geber, was a scholar of the early Islamic world whose writings on alchemy, chemistry, pharmacy, and metallurgy laid much of the practical foundation of chemical knowledge. His life is poorly documented and many details are uncertain. He is traditionally said to have been born in Tus in Khurasan, in what is now northeastern Iran, to an Arab family of the Azd tribe, and to have worked at the Abbasid court in Baghdad and Kufa under the patronage of the Barmakid family, the powerful viziers of the Caliph Harun al-Rashid. When the Barmakids fell from favour in 803, Jabir reportedly retreated from public life. The scale of the writings attributed to him — several thousand treatises — is far larger than any single person could have produced, and modern scholars now believe that many works under his name were written over two or three centuries by a group of scholars associated with a particular religious and philosophical tradition, possibly the Ismaili branch of Shia Islam. Whether Jabir was a single historical person who founded the tradition, a legendary name used by later writers, or both at once, the Jabirian corpus represents one of the richest bodies of alchemical and chemical writing ever produced. It was translated into Latin from the twelfth century onwards and shaped European alchemy, through which it helped seed the eventual emergence of modern chemistry.

Abu Bishr Amr ibn Uthman, known as Sībawayh (c. 760-796), was a Persian-born Arab grammarian whose book Al-Kitāb is the first comprehensive description of the Arabic language and one of the most important works in the history of linguistics. He was born in Hamadan or Shiraz, in what is now Iran, into a Persian family. Arabic was not his first language. He moved to Basra, in what is now Iraq, as a young man. Basra was then one of the great centres of Islamic learning, with mosques, schools, and scholarly circles that drew students from across the expanding Muslim world. Sībawayh studied with the leading Arabic grammarians of his time, including the great al-Khalīl ibn Ahmad, who had developed systematic approaches to Arabic phonology and had produced the first Arabic dictionary. Sībawayh was especially devoted to al-Khalīl and quotes him extensively in his own work. Sībawayh's nickname in Persian means little apple, and may have come from the apple-like freshness of his complexion. He lived a short life of about thirty-six years but produced a single enormous book that remains the foundation of Arabic grammatical science. The book is simply called Al-Kitāb, which means The Book — as if it were the only book that needed saying much about. This was not arrogance but recognition by the tradition that followed: for over twelve centuries Arabic grammarians have treated Al-Kitāb as the definitive starting point for their field. Sībawayh died young, possibly around 796. The details of his death are uncertain. One traditional story holds that he died shortly after losing a famous grammatical debate in Baghdad against a rival scholar. This story may not be historically reliable. What is certain is that his book survived him and became the foundation of Arabic linguistics, studied continuously from his own time until today.

Muḥammad ibn Mūsā al-Khwārizmī was a Persian scholar born around 780, probably in Khwarezm, a region in what is now Uzbekistan. His family name, al-Khwārizmī, means 'from Khwarezm'. He spent most of his working life in Baghdad, the capital of the Abbasid Caliphate. Baghdad at that time was one of the world's great centres of learning. He worked at the House of Wisdom, a famous library and research centre set up by the Caliph al-Ma'mūn. Scholars there translated Greek, Persian, and Indian texts into Arabic and wrote original works of their own. Al-Khwārizmī was one of the most important scholars of his generation. He wrote on mathematics, astronomy, geography, and the calendar. His most famous book is usually called al-Kitāb al-mukhtaṣar fī ḥisāb al-jabr wa'l-muqābala, or The Compendious Book on Calculation by Completion and Balancing. The word al-jabr in the title gave us the English word algebra. Another of his books explained how to calculate using the Hindu numerals from India. This book, translated into Latin centuries later, spread these numerals across Europe. We call them Arabic numerals today, but they came from India through scholars like him. He died around 850. Many of his works survive. Some exist only in later Latin translations. His influence on mathematics is hard to overstate.

Ibn Sina (980-1037 CE), known in the Western world as Avicenna, was a Persian Muslim philosopher and physician. He was born near Bukhara in what is now Uzbekistan. He was exceptionally gifted: he is said to have memorised the Quran by age ten, and by eighteen was a practising physician whom established doctors came to consult. He lived an active and often difficult life, working as a physician and court official for various rulers across Central Asia and Persia while writing philosophy and science at an extraordinary pace. He wrote more than 200 books. His most important works are the Canon of Medicine, which became the standard medical textbook across Europe and the Islamic world for five centuries, and the Book of Healing (Kitab al-Shifa), a massive encyclopaedia of philosophy and science. He died at 57 years old, in 1037 CE, in what is now western Iran.

Jalal al-Din Muhammad Rumi (1207-1273), known throughout the Islamic world as Mawlana (our master) and in the West by the short name Rumi, was a Persian Sufi poet, theologian, and teacher whose work remains among the most widely read religious poetry in world literature. He was born in Balkh (in present-day Afghanistan), then part of the Khwarezmian Empire, into a family of religious scholars. His father Baha al-Din Walad was a respected teacher and preacher. The family fled westward before the Mongol invasions, travelling through Baghdad, Mecca, Damascus, and finally settling in Konya in the Seljuk Sultanate of Rum (in present-day Turkey) — the origin of the name by which he became known. Rumi received thorough training in Islamic law, theology, and the Persian poetic and philosophical tradition. By his thirties he was a respected scholar and teacher with his own students and a conventional scholarly career. In 1244 he met a wandering dervish named Shams al-Din of Tabriz. The encounter transformed him. For nearly three years the two were inseparable, engaged in intense spiritual conversation. When Shams disappeared — either killed by Rumi's jealous disciples or simply leaving — Rumi responded not with a return to conventional scholarship but with an outpouring of poetry. The Diwan-i Shams-i Tabrizi, a collection of over forty thousand verses of lyrical poetry dedicated to his lost friend, and the Masnavi-i Ma'navi, a six-book epic of some twenty-five thousand couplets often called the Persian Qur'an, are the main works of his later life. He also wrote prose works and letters. The Sufi order later founded by his followers — the Mevlevi, famous for the whirling dance that became a form of prayer — spread across the Ottoman world. He died in Konya in 1273 and was buried there; his tomb at the Green Mausoleum remains one of the most visited religious sites in the Islamic world. UNESCO declared 2007, his eight-hundredth birth anniversary, an international year of Rumi.