The Fatimid dynasty in Egypt (AD 969 to 1171) supported royal libraries most notably the Dar al-ʿIlm, the House of Knowledge, begun by Al-Hakim bi-Amr Allah ("The Ruler by the Order of God"). 1 The works in the library belonged to all categories of secular and religious knowledge. Many were of great artistic value because they were executed by the greatest calligraphers specializing in “proportionate writing” (al-khatt al-mansûb), an art from Baghdad.
Dar al-ilm, was endowed with books on a range of subjects, from Al-Hakim’s own palace treasury who paid for the scholars to teach open to all who wished to study. The chronicler Ibn Abi Tayyi, wrote the following account of the Fatimid library:
“It was one of the wonders of the world, and it was said that in all the lands of Islam there had been no greater library than the one in the palace of Cairo.”
When this palace library was plundered by Turkish soldiers in the year 1068 it consisted of forty rooms. The works of classical authors alone comprised 18, 000 volumes” 2 According to al-Maqrizi, some of the books fell into the hands of Berber tribesmen who reputedly used some of the covers to make sandals. As for the pages, they were burned for fuel, and their ashes “formed great hills” that in al-Maqrizi’s day were called tilal al-kutub—hills of books.3
Walker, P. E. (2016). Libraries, Book Collection and the Production of Texts by the Fatimids, Intellectual History of the Islamicate World, 4(1-2), 7-21.
Heinz Halm, The Fatimids and their Traditions of Learning, I.B. Taurus & Co Ltd., New York, 1997.
Verde, Tom (2019) Cairo’s House of Knowledge. Aramco World.(Jan/Feb).
I'm astounded we have any books left whatsoeer.