Well the "golden age" they were reaving the world and sacking ancient cities stealing wealth and knowledge and enslaving huge numbers of people.  Did they have advanced society because they kept slaves to run it? I wonder what they took from the Library of Alexandria for example, before they burned it the last time.  Byzantium as well and a good chunk of Europe. There is a website https://gatesofvienna.net/ that discusses this and the false history we are taught. (Ie Crusades were evil europeans invading ME).  I hate trying to navigate it on my phone though. Article or excerpt from a book (I need to find a copy) about the Dark Ages being caused by the rise of Islam https://gatesofvienna.net/2009/10/islam-and-the-dark-age-of-byzantium/