Infidel Kings and Unholy Warriors by Brian A. CatlosRead about the other entries on the list.
Most reasonably well informed people already know that Spain under the Moors was a vibrant cultural melting pot. This book digs deeper, describing the place in fascinating detail and then moving on to Sicily, Alexandria, and Palestine during the centuries that culminated in the Crusades.
Neal Stephenson was of the 20 biggest science fiction movers-and-shakers of 2008.
--Marshal Zeringue