I greatly appreciate the effort that had been exerted to cover such eventful eras in less than 500 pages.It must have been an arduous task.Nonetheless,I would have given the book 5 stars had it been merely historical.Much more attention should have been paid to the political history of Islam,the development of the state in it,how the Caliphs contributed (or not)to establishing a real democracy.The authors,I think,could have been more critical.So much information and so little order and linking.History,I believe,is one endless chain,one event leads to another.The authors have unfortunately been ignorant of this simple fact.