Books like The Heirs of Muhammad
Barnaby Rogerson
The Heirs of Muhammad is 424 pages, about 7 hours 46 minutes at 250 words a minute.
9 books to read next
How long each takes
Islam 4.2 h 
No God but God 5.7 h 
A History of Islamic Societies 18.4 h 
Introducing Islam 6.5 h 
The Oxford History of Islam 13.7 h 
Daily Wisdom: Sayings of the Prophet Muhammad 7.3 h 
Medieval Islamic Medicine 4.1 h 
Islam's Black Slaves 5.3 h 
A Short History of Islam 8.1 h Bar height shows length. Estimated at 250 words a minute.