Martin Luther, the Ottoman Turks, and the Siege of Vienna

The Ottoman Empire was the most powerful country in the world in the sixteenth century. The Ottoman state began in the fourteenth century, ever expanding, conquering by holy war in the name of Allah. It crushed the 

Byzantine Empire, capturing Constantinople in 1453. The Ottomans reached the apex of their power under Sultan Suleyman, who held power during the years of the Protestant Reformation. Suleyman began his campaign to take Vienna by setting out on May 10, 1529, with a force of at least seventy-five thousand men consisting of cavalry and elite janissary foot soldiers.

Dangerous Days
When Martin Luther published On War Against the Turk in 1529, he realized that the territorial integrity of the heartland of Europe looked dubious. The Turks could not be stopped. Before the forces of Suleyman, two citadels had fallen in succession, Belgrade (1520) and Rhodes (1521). The Hungarians had been massacred at Mohacs (1526). When Luther penned his treatise, Suleyman was poised to strike again. Luther wrote, “It is a fact that the Turk is at our throat.”1

The Turks were invincible, Luther affirmed, because they were energized by the devil. He stated, “I believe that the Turk’s Allah does more in war than they themselves. He gives them courage and wiles; he guides sword and fist, horse and man” (183). Luther contended that it would take a miracle to defeat them (184).

From Luther’s perspective, the Turks were “the army of the devil” (193). Much of their power resided in their overwhelming size. Luther drew a distinction between the strength of the sultan and that of the governments in Europe. “Fighting against the Turk,” he insisted, “is not like fighting against the king of France, or the Venetians, or the pope; he is a different kind of warrior.” Luther drew attention to the size of his army: “The Turk has people and money in abundance.” He conjectured on the number of troops that the Turks could field: “His people are always under arms so that he can quickly muster three or four hundred thousand men” (202).

Spiritual Counsel
To European Christians, Luther gave spiritual counsel, providing the exhortation that they must “fight against” the Turk “with repentance, tears, and prayer” (184). Repentance must be the starting point. “We must reform our lives,” he warned, “or we shall fight in vain” (171). Prayer was to be continuous, offered during the everyday activities of life. Every believer ought to raise to Christ, Luther wrote, “at least a sigh of the heart for grace to lead a better life and for help against the Turk” (173). The Christian’s prayer was to be directed against the Ottoman army that was on the verge of conquering all of Europe: “We must pray against the Turk as against other enemies of our salvation and of all good, indeed, as we pray against the devil himself” (175). Luther encouraged his readers, “Let everyone pray who can that this abomination not become lord over us” (178).

Military Advice
Luther also advised the political elite of his time. He began by urging the princes of Europe to unite so that they would confront Suleyman with a massive force, rather than engaging him single-handedly. He reflected on the disaster at Mohacs on August 29, 1526, in which Suleyman obliterated the army of King Louis II, wiping out the Christian kingdom of Hungary. The fundamental problem at Mohacs was that the Hungarians were outnumbered three to one. Suleyman had at least seventy thousand men, while Louis fielded a much smaller force of some twenty-four thousand men. The approach of meeting Suleyman one king at a time was not working. “The Turk devours them one after another,” observed Luther (202).

He also set forth his opinion regarding the makeup of the fighting force that needed to be assembled against Suleyman. “The pope and his bishops,” he asserted, “would be deserting their calling and office to fight with the sword against flesh and blood. They are not commanded to do this; it is forbidden” (165). He referred to the military activities of Pope Julius and Clement, “who people think is almost a god of war” (169). As to the bishops who engaged in combat upon the field, he asked, “How many wars . . . have there been against the Turk in which we would not have suffered heavy losses if the bishops and clergy had not been there?” (167).2

Bishops had a spiritual work to do, to give themselves as shepherds of the flock of Christ, to preach the Word of God (165–67). While they were to stay at home attending to their pastoral duties, Emperor Charles V and the princes were to take the initiative, to unfurl the banner upon which was written “Protect the good; punish the wicked.” If the emperor had done what he was called to do, reasoned Luther, “the princes would have followed” his leadership, “and the Turk would not have become so mighty” (190).

Rain from Heaven
Suleyman never got past Vienna in his attempt to conquer the European heartland. Although he had left Constantinople in May 1529 with a large invading force, four and a half months would pass before he was able to launch an attack upon the fortified city of Vienna on September 30. Bombardments and efforts to mine the walls followed. The walls withstood everything that was thrown at them. A couple of weeks later he had to withdraw. What happened? The summer of 1529 brought torrential rains of a kind that had not been seen for many years. The deluge meant that Suleyman was not able to move his massive cannons, the kind of artillery that were useful in knocking holes in massive walls of cities. The rain kept coming, and the Turks were slowed down in their advance. Vienna was reinforced with German Landsknechte pikemen and Spanish musketeers. Suleyman had neither the time nor the artillery that he needed. The snow fell early. The food supply dwindled. Casualties mounted. Soldiers fell with illness. The mighty sultan gave up the siege. Central Europe was spared.


1. Martin Luther, “On War Against the Turk,” in Luther’s Works, vol. 46, ed. Jaroslav Pelikan et al. 
(St. Louis: Concordia; Philadelphia: Fortress, 1967), 204. All quotations in this article are from this treatise.
2. It could be that Luther had in mind the slaughter at Mohacs of not only the king of Hungary but also two archbishops and five bishops..

Dr. Mark J. Larson
is a teacher and pastor on the campus of 
Cono Christian School in Walker, IA.