The Caliph Haroun Al-Rasheed (also written Harun Al-Rashid, who reigned for 23 years from 786-809 CE) built a magnificent Scientific Academy (Majma' ‘Ilmi) in which was housed a huge bookstore (Khizanat Kutub) containing manuscripts and books about various subjects in the arts and the sciences and in different languages. (MJ & AS, p. 130)
These works were collected by three successive generations of Caliphs: First by his grandfather the Caliph Abu Ja'far Al-Mansour (also written Al-Mansur, who reigned for 21 years from 754-775 CE and who built The Round City of Baghdad in 762-766 CE). Secondly, by his father Caliph Mohammad Al-Mahdi (who reigned for 11 years from 775-785 CE). Thirdly, by himself when he came across them during his travels, campaigns and expeditions. This Scientific Academy was called the House of Wisdom (Bayt Al-Hikma and Dar Al-Hikma). (MJ & AS, p. 130)
Strictly speaking from a linguistic point of view, in Arabic, the term Bayt refers to one roofed space which has a corridor (Dihleez), while Manzil denotes a complex containing more than one Bayt, a covered court (Sahn Musaqqaf) and a kitchen (used by a man and his family), while again a Dar refers to a bigger complex containing more than one Bayt and more than one Manzil and a courtyard opened to the sky. Hence, in the ascending hierarchy of size and spaces, it is a Bayt, a Manzil and a Dar. However, people tend to use Bayt, Manzil and Dar interchangeably. (Muhit-ul-Muhit)
The Abbasids' House of Wisdom in Baghdad (Bayt Al-Hikma) was referred to as such during the reign of the Caliph Al-Rasheed. However, when his son Al-Ma'moun became a Caliph, he expanded and extended Bayt Al-Hikma to become truly Dar Al-Hikma with one wing (Riwaq) for each subject. (MJ & AS, p. 130)
The House of Wisdom was also referred to as Al-Hikma Bookstore (Khizanat Al-Hikma), and The House of Wisdom Bookstore of Al-Ma'moun (Khizanat Dar Al-Kutub Al-Ma'mouniya). It should be pointed out that the Arabic term Khizanat Kutub, meaning literally a bookstore, is an old name meaning a present day library.
In this Academy, translators, scientists, scribes, authors, men of letters, writers, authors, copyists and others used to meet every day for translation, reading, writing, scribing, discourse, dialogue and discussion. Many manuscripts and books in various scientific subjects, and in different languages were translated there. (MJ & AS, p. 130)
The languages which were spoken, read and written there were Arabic (as the lingua franca), Farsi, Hebrew, Aramaic, Syriac, Greek and Latin; also occasionally Sanskrit, which was used to translate the old Indian manuscripts in astronomy and mathematics.
The Caliph Abdulla Al-Ma'moun (who reigned for 20 years from 813 to 833 CE) and who was the son of the Caliph Haroun Al-Rasheed extended and expanded the House of Wisdom (Bayt Al-Hikma) and designated a gallery (Riwaq) for each branch of science (‘Ilm). Many scientists (‘Ulama') in the Arts and Sciences, famous translators, commentators and authors, etc were daily working in the House of Wisdom (reading, translating, copying, commenting, and writing as well as taking part in dialogue, discussions and discourse. (MJ & AS, p. 130)
Among the famous translators was Hunayn bin Ishaq (Isaac) Al-‘Ibadi, who translated some of the works by the Greek physician Hippocrates. (MJ & AS, p.130 quoting Al-Qifti, p.248)
Al-Ma'moun made Hunayn the Head of the Translation Department (Diwan Al-Tarjama). Hunayn was good in four languages: Syriac, Arabic, Farsi and Greek. It is reported that the Caliph used to give him the equivalent weight in gold to that of the books he had translated into Arabic. Hence, it is also reported that Hunayn used to choose for his translated books the thickest of the paper, and used to order his scribes to write in big letters and to make a wide margin between the lines. Hunayn had translated many books from Farsi, Greek and Syriac.(MJ & AS, p. 132). (Although this story has been reported, the author wonders how true it is, and how many times it had happened, for such excessive generosity would have bankrupted the Treasury of the Caliphate (Bayt Al-Maal). It also does not put Hunayn in good light, giving the impression of being greedy and selfish).
It is said that Al-Ma'moun had heard about the magnificent Sicily Library, so he wrote to the King of Sicily asking him for the entire content of the Sicily Library (which was rich in philosophical and scientific books of the Greeks) to incorporate it in the library of the House of Wisdom. The King on the advice of his bishops (that the contents of these books did no good to the people of the Ancient World) sent the content of the Sicilian Library to the Caliph. (MJ & AS, p. 131)
It is also said that Al-Ma'moun used the load of one hundred camels to transport from Khurasan (in north east Persia) to Baghdad magnificent hand-written books and manuscripts to include them in the library of Dar Al-Hikma. Hence, Al-Ma'moun took special interest in translation and transcription. (MJ & AS, p. 131)
Al-Ma'moun requested the Byzantine Emperor at the time for permission to send some of his scientists (‘Ulama') to translate the useful books, which were stored in the Empire; the Emperor replied positively to his request. The Caliph then sent out some of his scientists, and ordered them to translate what they could of the Greek and to correct what others had translated. Among the scientists the Caliph had sent out were Al-Hajjaj bin Mater, Ibn Al-Batreeq, Salam bin Haroun (the keeper and supervisor of Bayt al-Hikma), Youhanna bin Masawayh and Hunayn bin Ishaq. (MJ & AS, pp. 131 & 132)
It is important to point out that Al-Ma'moun (who was fluent in Arabic and Farsi for his mother was Persian from Khurasan) used to preside over and actively participate with the scientists, scholars and wise men their seminars, discourses and discussions of various subjects in the Arts and the Sciences. (MJ & AS p.130)
Within the library of the House of Wisdom, there may well have been separate libraries for the collection of different Caliphs: Al-Mansour, Al-Mahdi, Al-Rasheed, and Al-Ma'moun. There may well have been different keepers, supervisors and cataloguists for such libraries or collections.
It would seem from the above account that the House of Wisdom was in fame, status, scope, size, resources, patronage, etc. similar to that of the present day British Library in London or the Nationale Bibliotheque in Paris, in addition to being an Academy for the Arts and the Sciences where scholars came together for dialogues, discussions and discourses.
Al-Ma'moun built an astronomical observatory (Marsad Falaki) in the Shammasiya district of Baghdad and gave its running to Sanad bin Ali Al-Yahoudi who was known as Al-Ma'moun's Astronomer (Munajjim Ma'mouni), and to Yahya bin Abi Mansour, and Khalid bin Abdil Malak. As a result of his observations and those of his colleagues, Sanad wrote a well-known Zeej or an ephemeris (which is a table of the calculated positions of a celestial object at regular intervals throughout a period). It is said that Sanad became a Muslim at the hands of Al-Ma'moun himself. (MJ & AS, p. 130)
Very sadly and tragically, the House of Wisdom came to a brutal end on 12 February 1258 CE with the Mongol invasion of Baghdad led by Hulegu (the grandson of Chingis Khan), who killed the last Abbasid Caliph Al-Musta'sim (despite his surrender to Hulegu in order to spare the destruction of the City of Baghdad and its cultural heritage); Hulego also ordered the slaughter of the Caliph's entire family and relatives, as well as all those in the Caliphate Court (Bilat Al-Khilapha). This was the end of the Abbasid Caliphate.
The magnificent collection of books and manuscripts of the House of Wisdom was thrown into the muddy waters of the River Tigris whose brown colour turned black for days as a result of the washing away of the ink used in the of the writing of these books and manuscripts.
In addition to the Library of the House of Wisdom, there were many other Baghdadi Libraries (Khaza'in Al-Kutub Al-Baghdadiya) attached to the many Faith Schools (Madaris, singular Madrasa), each containing thousands of books and manuscripts. (ref). There were also private individual libraries, which were not open to the general public, but were available to scientists, philosophers, researchers and writers. (NM, pp. 129-136 & 144-147; MJ & AS, pp. 254 & 255)
One must also mention that in some of the cities of the Eastern Provinces of the Islamic World, several "Houses of Science" (Dour Al-‘Ilm, singular Dar Al-‘Ilm), or more accurately "Houses of Knowledge", were established in the 9th and 10th Centuries to emulate that of Dar Al-Hikma in Baghdad. (MJ & AS, pp. 254 & 255; NM, p. 129) Such cities included Mosul, Basra, Shiraz, Rayy, etc. (Encycl. of Islam).
It is reported about Al-Ma'moun that he gathered a group of wise men (Hukama') and asked them to prepare a map of the world for him, and which they did; this was known as Al-Ma'mounite Picture (Al-Soura Al-Ma'mouniya). It far exceeded those, which were available during the lifetime of Ptolemy and other Greek geographers. Also, about twenty geographers wrote a book about geography for Al-Ma'moun. (MJ & AS, pp. 133 &134)
Al-Ma'moun took after his father Al-Rashid in establishing many higher institutes, observatories, and factories for textiles. It is said that the number of higher institutes during his reign reached 332, and they were packed with students pursuing various subjects in the Arts and in the Sciences.(ref). These were built in according to the finest style, and most of them were in mosques and monumental buildings (Mashahid); this figure excludes the equivalent of primary schools (Katateeb) not including schools.
He also built hospitals (Bimarstanat or Maristanat), which were crowded with their physicians, surgeons, Opthalmists, dentists, and their students (and of course as well as patients). (MJ & AS, p. 133)
It is important to put the House of Wisdom in the Context of the city of Baghdad as the Capital of the Islamic World during its Golden Age. Baghdad played a major part in the propagation and spread of knowledge in the Arts and in the Sciences and in the development of their material wealth.
Baghdad had reached its highest reputation and glorious status during the reigns of the Caliph Al-Rasheed. Its buildings had expanded widely on both banks and sides of the river Tigris, in a form of urbanism resembling that of contiguous towns, and its population had reached about one million. It was the centre for Islamic (if not the world) culture and civilisation, as well as the headquarters for the Arts, Sciences and Letters. It was crowded with Scientists, Physicians, Mathematicians, Astronomers, Men of Letters, Poets, Writers, Translators, Scribes, and Professionals in the various arts and crafts, etc.
Additionally, one must mention the Great Library of Cordoba of the Umayyad Dynasty in Andalusia with its thousands of magnificent books and manuscripts. One can only imagine its invaluable collection when one reads that after 1492 and during the Spanish Inquisition when about half-a-million of its priceless books and manuscripts were deliberately and callously burnt!
There were rivalry and competitions between these three libraries in obtaining the most magnificent books and manuscripts as well as in attracting the best scholars to work there. Such competitions were very beneficial to the advancement of scientific research and publications in the Islamic World.
It would not be an exaggeration to imagine camel caravans loaded with magnificent books and manuscripts criss-crossing the Islamic World on their way to reach the magnificent Libraries of Bayt or Dar A-Hikma in Baghdad, Dar Al-Hikma in Cairo or the Great Library of Cordoba.
Tragically, during the 2003 war in Iraq, the Central Library in Baghdad, the House of Islamic Manuscripts (Dar Al-Makhtoutat Al-Islamiya) in Baghdad, and many other university and public libraries in Baghdad, Mosul and Basra were pillaged and burnt down. The heritage contained in the Iraqi Museum suffered the same.
A point has to be made here about the term Medieval frequently used in civilization literature. It is not acceptable to speak of "Islamic Medieval Civilization", "Islamic Medieval Architecture", "Islamic Medieval Science", etc. This is because the term "Medieval" applies to European history only , for while Europe was asleep during the Dark Ages, Middle Ages, Medieval Ages, Islamic Civilization, Culture and Heritage were in ascendancy and reached their highest achievements in various parts of the Islamic World.
Proposed alternative terms may include: "Golden Age of Islam", "Golden Age of Islamic Civilization", "Islamic Age", "Islamic Era", "Islamic Epoch", "Islamic Time", etc.).