Well, by "many Islamic cultures" we're talking primarily about the Abbasid Caliphate, who had a religious arrangement whereby scholars were must-have prestige employees because interpreting the Koran was a great way to find new truths and you had to be scholarly for that. As such, knowledge flourished... until the inevitable fundamentalist backlash. Not that things ever got as bad as the Dark Ages but the Golden Age of Islam was at its peak while Europe was at its low.
And yes. The book covers Islam from Mohammed to about 2010.