So when the mobs came to burn the place down no one was there to stop them. Hmm.. there were no mobs involved, the first destruction is attributed to Caesar at

So when the mobs came to burn the place down no one was there to stop them. Hmm.. there were no mobs involved, the first destruction is attributed to Caesar at around 48BC. I appears that the library was then rebuild and destroyed again in 648AD ... Burning and destruction of the Library of Alexandria was reported to be the first act of sacking after Amr ibn al 'Aas forces entered the city. It was also said that the Library's collection was still substantial enough at this late date to provide six months' worth of fuel for the baths. From (http://en.wikipedia.org/wiki/Library_of_Alexandria http://en.wikipedia.org/wiki/Library_of_Alexandria)