Short answer: the House of Wisdom (Bayt al-Ḥikmah) was a library and centre of scholarship in Baghdad, Iraq, under the Abbasid caliphs, most famously al-Ma'mun (r. 813 to 833). It is linked with the translation of Greek, Persian and Indian works into Arabic. The wider Islamic Golden Age, roughly the 8th to the 13th century, gave the world algebra, the decimal number system in its Arabic form, advances in optics, medicine and astronomy, teaching hospitals and some of the oldest universities. Historians debate how big the House of Wisdom really was, and whether the Golden Age ended in 1258.
What was the House of Wisdom?
The Abbasid caliph al-Mansur founded Baghdad in 762 as his new capital, on the Tigris river. Under his successors, the palace held a growing collection of books, called in the sources Khizānat al-Ḥikmah (the storehouse of wisdom) and later Bayt al-Ḥikmah (the House of Wisdom).
| Question | Answer |
|---|---|
| Where was it? | In Baghdad, the Abbasid capital, in what is now Iraq |
| When? | It is linked with Harun al-Rashid (r. 786 to 809) and above all his son al-Ma'mun (r. 813 to 833) |
| What was it? | A royal library with translators, copyists and scholars attached to it; how much more is debated |
| What happened to it? | Baghdad was sacked by the Mongols under Hulagu in February 1258, and the libraries of the city were destroyed |
Accounts of the sack say so many books were thrown into the Tigris that the river ran black with ink. Historians treat the details of such reports with caution, but the destruction of the city's libraries is not in doubt.
What historians disagree about
Popular books describe the House of Wisdom as a grand academy, a kind of medieval university where all the great translators worked. Specialists are more careful:
- Dimitri Gutas (Yale), in Greek Thought, Arabic Culture (1998), argued it was mainly a palace library and bureau, and that the great translation movement was paid for by many patrons across Baghdad, not run from one building. He noted that the many reports about Greek-to-Arabic translation almost never mention the House of Wisdom.
- Ekmeleddin İhsanoğlu, in The Abbasid House of Wisdom: Between Myth and Reality (2023), reached a similar view: a palace library, enlarged into a myth by later writers.
- Jim al-Khalili, in The House of Wisdom (2011), keeps it at the centre of the story, while accepting that many of Baghdad's scholars were not physically based there.
What nobody disputes is the translation movement itself: from the late 8th century to the 10th, a large part of Greek science and philosophy was translated into Arabic in Baghdad, often by Christian scholars such as Hunayn ibn Ishaq, alongside Muslim, Jewish and Sabian scholars. Paper, which reached Baghdad by the end of the 8th century, made books far cheaper to copy.
Why did Muslims value learning so much?
The first word of the Quran to be revealed was a command to read:
ٱقْرَأْ بِٱسْمِ رَبِّكَ ٱلَّذِى خَلَقَ ﴿١﴾ خَلَقَ ٱلْإِنسَٰنَ مِنْ عَلَقٍ ﴿٢﴾ ٱقْرَأْ وَرَبُّكَ ٱلْأَكْرَمُ ﴿٣﴾ ٱلَّذِى عَلَّمَ بِٱلْقَلَمِ ﴿٤﴾ عَلَّمَ ٱلْإِنسَٰنَ مَا لَمْ يَعْلَمْ ﴿٥﴾
Iqra bismi rab bikal lazee khalaq Khalaqal insaana min 'alaq Iqra wa rab bukal akram Al lazee 'allama bil qalam 'Al lamal insaana ma lam y'alam
(1) Recite in the name of your Lord who created - (2) Created man from a clinging substance. (3) Recite, and your Lord is the most Generous - (4) Who taught by the pen - (5) Taught man that which he knew not.
Quran 96:1-5 · Sahih International · Read Surah Al-Alaq
The Quran asks: "Are those who know equal to those who do not know?" (39:9), and teaches the dua "My Lord, increase me in knowledge" (20:114). It tells believers to look at the sky, the earth and their own bodies as signs. The Prophet ﷺ said: "Seeking knowledge is an obligation on every Muslim" (Sunan Ibn Majah 224, graded sahih by al-Albani through its many routes, though some scholars weakened it). Practical needs played a part too: finding the qibla, working out prayer times and the Hijri calendar, and dividing inheritance all need mathematics and astronomy.
Contributions, with names and dates
Dates are approximate, as is usual for this period. Death dates are more certain than birth dates.
| Field | Scholar | Dates (CE) | What they did |
|---|---|---|---|
| Mathematics | Muhammad ibn Musa al-Khwarizmi | c. 780 to c. 850 | Wrote al-Kitab al-Mukhtasar fi Hisab al-Jabr wa al-Muqabalah, which gave us the word algebra. His name gave us algorithm. His book on Indian numerals spread the decimal place-value system that Europe later called Arabic numerals |
| Philosophy, science | Ya'qub ibn Ishaq al-Kindi | c. 801 to c. 873 | Called the philosopher of the Arabs. Wrote on optics, music and early cryptanalysis (frequency analysis) |
| Translation, medicine | Hunayn ibn Ishaq | 809 to 873 | The most productive translator of Greek medicine, especially Galen, into Arabic and Syriac |
| Engineering | The Banu Musa brothers | 9th century | Kitab al-Hiyal (Book of Ingenious Devices), with about a hundred mechanical devices |
| Medicine | Abu Bakr al-Razi (Rhazes) | c. 865 to c. 925 | Ran hospitals in Rayy and Baghdad; his treatise on smallpox and measles is among the first to tell the two apart |
| Surgery | Abu al-Qasim al-Zahrawi (Abulcasis) | c. 936 to c. 1013 | In Cordoba, wrote al-Tasrif, whose surgery volume illustrates some 200 instruments |
| Optics | Ibn al-Haytham (Alhazen) | c. 965 to c. 1040 | Kitab al-Manazir (Book of Optics) showed that we see by light entering the eye, and tested claims by experiment |
| Medicine, philosophy | Ibn Sina (Avicenna) | 980 to 1037 | al-Qanun fi al-Tibb (Canon of Medicine), used as a medical textbook in Europe for centuries |
| Astronomy, geography | Abu Rayhan al-Biruni | 973 to c. 1050 | Measured the earth's radius with a method using a mountain and the horizon; wrote a detailed study of India |
| Mathematics, astronomy | Omar Khayyam | 1048 to 1131 | Solved cubic equations geometrically; worked on the Jalali solar calendar |
| Geography | Muhammad al-Idrisi | c. 1100 to c. 1165 | Made a world map and geography for Roger II of Sicily (1154) |
| Engineering | Ismail al-Jazari | 1136 to 1206 | Book of Knowledge of Ingenious Mechanical Devices (1206): water clocks, pumps and automata |
| Medicine | Ibn al-Nafis | 1213 to 1288 | Described the pulmonary (lung) circulation of the blood, centuries before it was known in Europe |
| History, society | Ibn Khaldun | 1332 to 1406 | al-Muqaddimah (1377), an early study of how societies rise and fall |
Hospitals, universities and observatories
- Hospitals (bimaristan). Large hospitals with wards, pharmacies and teaching were founded in Baghdad, in Cairo (the hospital of Ahmad ibn Tulun, 872), in Damascus (the Nuri hospital, 1154) and again in Cairo (the Mansuri hospital, 1284). They treated patients free of charge, funded by endowments (waqf).
- Universities. The Qarawiyyin mosque in Fez, Morocco, was founded in 859 by Fatima al-Fihri, and grew into a centre of learning that Guinness World Records lists as the oldest existing, continually operating educational institution in the world. Al-Azhar in Cairo began with its mosque in 970 to 972. Historians debate whether the word university fits their early form.
- Observatories. The Maragha observatory in Iran (founded 1259) under Nasir al-Din al-Tusi, and Ulugh Beg's observatory in Samarkand (1420s), produced star tables used for centuries.
- Women in learning. Mariam al-Ijliya, called al-Asturlabiyyah, made astrolabes in 10th-century Aleppo, as recorded by Ibn al-Nadim. Women also taught hadith in large numbers, as Mohammad Akram Nadwi has documented.
How the knowledge reached Europe
From the 11th and 12th centuries, scholars in Toledo, Sicily and elsewhere translated Arabic books into Latin. Gerard of Cremona alone translated dozens, including Ibn Sina's Canon. Leonardo of Pisa (Fibonacci) learned the Hindu-Arabic numerals in North Africa and spread them in his Liber Abaci (1202). Many star names still used in astronomy, such as Aldebaran and Altair, come from Arabic.
When did the Islamic Golden Age end?
Textbooks often end it with the Mongol sack of Baghdad in 1258. Many historians now reject a sharp end. George Saliba, in Islamic Science and the Making of the European Renaissance (2007), shows that astronomy reached some of its best work after 1258, at Maragha and with Ibn al-Shatir in 14th-century Damascus. Science and scholarship also continued in the Ottoman, Safavid and Mughal worlds. A fair summary: the Abbasid centre fell in 1258, but learning in the Muslim world did not.
Questions
What is the definition of the House of Wisdom?
The House of Wisdom (Bayt al-Hikmah) was the Abbasid royal library and centre of scholarship in Baghdad, linked with the translation of Greek, Persian and Indian works into Arabic in the 9th century, especially under the caliph al-Ma'mun.
Where was the House of Wisdom located?
In Baghdad, the capital of the Abbasid caliphate, in present-day Iraq.
Who founded the House of Wisdom?
The sources link it with Harun al-Rashid (r. 786 to 809), whose library it may have been, and with his son al-Ma'mun (r. 813 to 833), who expanded it. Some reports trace the book collection back to al-Mansur.
What did the Islamic Golden Age contribute to the world?
Algebra, the spread of the decimal number system, experimental optics, major medical textbooks, surgical instruments, teaching hospitals, observatories and the preservation and development of Greek philosophy and science.
Why did the Islamic Golden Age end?
The conventional answer is the Mongol sack of Baghdad in 1258. Many historians argue there was no single end: science continued at Maragha, Damascus, Samarkand and in the later empires.
Sources
- Quran 96:1-5, 39:9, 20:114. Translation by Sahih International. Sunan Ibn Majah 224.
- Dimitri Gutas, Greek Thought, Arabic Culture: The Graeco-Arabic Translation Movement in Baghdad and Early Abbasid Society (Routledge, 1998).
- Ekmeleddin İhsanoğlu, The Abbasid House of Wisdom: Between Myth and Reality (Routledge, 2023).
- Jim al-Khalili, The House of Wisdom: How Arabic Science Saved Ancient Knowledge and Gave Us the Renaissance (Penguin, 2011).
- George Saliba, Islamic Science and the Making of the European Renaissance (MIT Press, 2007).
- Encyclopaedia Britannica and the Encyclopaedia of Islam (Brill), entries on each scholar named, for dates. Ibn al-Nadim, al-Fihrist, on Mariam al-Asturlabiyyah. Mohammad Akram Nadwi, al-Muhaddithat: The Women Scholars in Islam (2007).
- Guinness World Records, oldest university (al-Qarawiyyin, Fez).
The dates and facts on this page come from the sources listed. Where historians differ, we say so. The religious content is pending review by the scholars on our team.