Confronted with the military advance of the Turkish Ottoman Empire against the Holy Roman Empire, including the siege of Vienna, Martin Luther wrote several treatises on the Turks. Luther rejected the idea of a war in the name of religion against the Ottoman onslaught, seeing instead the defense of the Holy Roman Empire as the duty of the Emperor. Luther understood the Turkish threat as God’s punishment for the laxity of Christians and so called for repentance and a return to the gospel. Luther wanted the Christians to have firsthand information about Islam and promoted a translation of the Qur’an in German against many obstacles. The Protestant church in Germany is very cautious about defining a present-day application of Luther’s approach.