In God's Path: The Arab Conquests and the Creation of an Islamic Empire - Robert G. Hoyland - Google Books

https://books.google.de/books?id=i3LDBAAAQBAJ

In just over a hundred years--from the death of Muhammad in 632 to the beginning of the Abbasid Caliphate in 750--the followers of the Prophet swept across the whole of the Middle East, North Africa, and Spain. Their armies threatened states as far afield…