JIHAD in the West
Muslim Conquests From The 7th To The 21st Centuries
By Paul Fregosi
Prometheus Books, 1998
ISBN 1-57392-247-1
My only criticism is that it should have been 5 volumes. Events are telescoped so much that it leaves you hungry for answers to the obvious questions generated.
But it is the most enjoyable non-fiction book I have read in months.
The discussion of Jannissaries is particularly of interest.