The given book is certainly interesting, and one can get a general view of what were those "rulers of Mecca", where they came from and so on. But for those interested in some certain period of Mecca's life the book offers only small bits of information, for it's aim is a bit vague, and it covers just too big a piece of time to give certain details, which, no doubt, are of interest. So, the book may serve as a good starting point to study the history of Hijaz, yet no more, and after reading it (if interested) one has to search further for more to satisfy his appetite.