Snouck Hurgronje, Christiaan: Mohammedanism. v1. 20 Jan 2014
 

Christiaan Snouck Hurgronje (1857-1936) was a Dutch scholar of Oriental cultures and languages and one of the first Western scholars to be allowed to take part in the annual pilgrimage to Mecca. (He had converted to Islam prior to his pilgrimage.)

He was also one of the first Western visitors to take photographs of Mecca and its surroundings.

His book Mohammedanism - Lectures on Its Origin, Its Religious and Political Growth, and Its Present State is a collection of lectures that he gave at prestigious universities in the USA in 1913.

Even though 100 years have passed since he gave his lectures, IMHO, they're still relevant today.