I am not sure how historian writing a book on knowledge under attack, conveniently missed one single biggest related event involving two of the world's history biggest empires, i.e. the ransack of Baghdad, at the time center of knowledge of the Abbasids empire and the world, by the Mongols [1]?

It is reported that after the defeat of the Abbasids, the trashing of the books caused the rivers around Baghdad turned its color into the color of the black ink. The event practically ended the Islamic golden age since Baghdad was the center of the world knowledge after Alexandria by translating much of the work of the Greek and contributing their own. There is also the location of the famous House of Wisdom, where Al-Khwarizmi was one of the heads, who wrote the first book on modern algebra and the word "Algorithm" is named after his name [2]. It is also reported that at the time books are so precious and at one time Ptolemy's Almagest was claimed as a condition for peace by the Caliph Al-Ma'mun after a war between the Abbasids and the Eastern Roman Empire. Perhaps some of the later discoveries or not yet to be discovered knowledge, have already discovered at the time and it was lost forever due to the ransacking of Baghdad by the Mongols.

The saving grace is that there's a another Islamic Spanish empire in Europe but fortunately the Spanish did not destroy the books but study them after the conquest of Toledo in 1083AD. It's probably not an exxageration to say that the western Renaissance started in Toledo, the city of knowledge for the Muslim Spanish empire, then spread to the rest of Europe[3]. The knowledge spread to the rest of Europe is further accelerated after the invention of printing press and books by Gutenberg in Germany, and as they say the rest is history.

[1]https://en.m.wikipedia.org/wiki/Siege_of_Baghdad_(1258)

[2]https://en.m.wikipedia.org/wiki/House_of_Wisdom

[3]https://www.bbc.co.uk/religion/religions/islam/history/spain...