While kings and generals worried about the military threat of the Ottoman Empire and the armies of Sultan Suleyman (1520-66) in the Balkans, Luther (1483-1546) worried that Islam would lure Christians from their faith. Francisco (theology, Concordia Theological Seminary, Indiana) examines the Protestant reformer's critique of Islam and defense of Christianity, finding them to be more theological and apologetic then is generally acknowledged. The study began as his 2006 doctoral dissertation at the University of Oxford. Annotation ©2007 Book News, Inc., Portland, OR (booknews.com)