How did Islam destroy the classical world?

[abaris]

One thing they did do is destroy Egyptian's cultural heritage. There were many centuries where not one Egyptian knew they ancient history or could read Egyptian hieroglyphs!

Simply wrong, unless you are speaking of the 16th century and later. Egypt already was Greek after Alexander taking over. Egypt was one of the first christian regions also. And in Egypt the first christian fundamentalists cropped up. Ultimately they were responsible for the loss of the Egyptian heritage, since they destroyed everything not being christian. The writings, the monuments, everything. Not to mention the destruction of the library of Alexandria in Caesar's time, which accounts for a huge cultural loss too.