Blood of the Templar by D. H. Nations

"Josephine Mowbray flees the butchering of her family at the hand of the Isma'ilites and stumbles into the protecting arms of the Knights Templar. But the Templar are not what they seem, and their mystery will lead Josephine on a journey that changes the very blood in her veins and condemns her to the world of night.

The Blood of the Templar pivots between the vampire knights who have remained true to their Christian faith, the Muslim assassin seeking to honor Allah by purging the demon-knights from his land, and the Knight Hospitaller attempting to expose the Templar's corruption to the Holy Church." (From Amazon.com)

Paperback Info: ISBN 1554046564, Double Dragon Publishing, 2009