Prior to the Reformation the Christian West was a religiously intolerant society regarding the non-Christian world, particularly its most powerful nearby state, the Ottoman Empire, as infidels representing a threat to Christians; thus “the Turks” were regarded as incarnations of the devil and a suitable target for holy war in the form of crusades. Beginning with the Reformation, however, a less monolithic, more individual and private view of Christianity arose, along with the loss of Christian unity and widespread inter-Christian intolerance. This led to growing rejection of the old bellicose Christianity preached by crusading popes and its accompanying stereotypical view of an “evil” Ottoman Empire. The article traces the development of European thought in the 16th-19th centuries on the value and necessity of religious toleration and changing attitudes and understanding in Europe regarding the Ottoman Empire. The latter was gradually perceived for what it was: an expansionist empire like many others, but not an incarnation of evil. Moreover, the Ottoman Empire was perceived as a political entity in which there was a remarkable degree of religious toleration relative to its Christian counterparts.