Yes, and was a center for learning in the world, a collection from the known world , I'm sure the knowledge lost there would have solved some of the arguments on this thread. That happened during Africa's developmental stage ... The conquest from Islamic armies and others
The Library at Alexandria was destroyed by the Romans, nothing to do with Islamic armies.
This from my book "Islamic Jihad" (p. 247, ref. clxxxii):
Some modern scholars, such as Phillip K Hitti, deny this (Omar's destruction of the library) on the ground that the Library of Alexandria could not exist because it was destroyed during the invasion of Julius Caesar in 48 BC. But, according to Theodore Vrettos (Alexandria, City of the Western Mind , The Free Press, New York, 2001, p. 93-94): "CaesarÂ’s soldiers set fire to the Egyptian ships, and the flames, spreading rapidly in the driving wind, consumed most of the dockyard, many structures near the palace, and also several thousand books that were housed in one of the buildings. From this incident, historians mistakingly assumed that the Great Library of Alexandria had been destroyed, but the Library was nowhere near the docksÂ… Some 40,000 book scrolls were destroyed in the fire, which were not at all connected with the Great Library; they were account books and ledgers containing records of AlexandriaÂ’s export goods bound for Rome and other cities throughout the world."
Well whether it was the Romans earlier, or The Umar Caliphate in 640 the knowledge was lost for that part of the world especialy.
There are some experts who say it was the muslims and some who say it was the Romans I suppose.
Personaly I would think the Ancient Egyptians were probably some mixture of peoples throughout their empires