Ages. It would be absurd to claim it as a work of original research;
it does not profess to trace the development of Islam as a religion,
and it omits all but the briefest mention of Muslim Spain and
India. I have tried to indicate the main trends of Islamic historical
evolution down to the Mongol conquests, to avoid a mere recital
of facts and names and dates, and to explain rather than to narrate.
Hence I have exercised a rigid selection of material; much of
moment has been left out, and the picture presented may often be
unavoidably over-simplified.