VIENNA 27 September–14 October 1529

An Ottoman depiction of the siege from the 16th century, housed in the Istanbul Hachette Art Museum

Forces Engaged

Austrian: 16,000 troops and 72 guns. Commander: Philip, count palatine of Austria

Ottoman: c. 120,000–125,000 (some sources claiming 300,000) Commander: Sultan Suleiman.


Turkish defeat at Vienna was the high-water mark of Ottoman expansion in Europe, signaling the beginning of a long decline in Ottoman power.

Historical Setting

Europe in the 1520s presented to a potential outside aggressor a wonderful opportunity, just as the weakened condition caused by Byzantine-Persian hostility had opened the door for Islam to break out of Arabia in the seventh century. More than weakness, however, it was political rivalry in Europe that made the continent vulnerable. Politically, King Francis I of France and Charles V, Holy Roman Emperor, argued and fought over land that today is the Franco-German frontier, as well as control over northern Italy. France had a powerful military based on artillery and heavy cavalry, with which it won a number of victories. Charles, as head of the Hapsburg family, controlled not only the Holy Roman Empire (which consisted of Austria and parts of whatever countries bordered it) but also Spain, whose military power was based on the tercio, a phalanx of pikemen supported by smaller contingents of soldiers, each armed with the harquebus, a matchlock musket. Against these formations, cavalry made no impression, and, when the two armies met at Pavia in northern Italy in 1525, France came up the loser. Ferdinand not only was defeated, he was taken prisoner. During and after his captivity, he plotted revenge and pondered on possible allies.

Although Charles was enjoying this military success, he was bothered by Pope Clement VII in Rome. Although technically the Holy Roman Empire was supposed to be the defender of the Catholic Church, just which was the senior partner in the equation had been a point of difficulty since Charlemagne took on the job in 800. Clement resented Charles for controlling so much of Italy because, before his accession to the papacy, Clement had been Giulio de Medici, a wealthy and powerful figure in his own right. Thus, Clement’s attitude toward Charles meant not only a lack of political support but also a lack of religious support in dealing with the rise of the Protestant Reformation and the increasingly political activities of Martin Luther in Germany. Thus, Charles had his hands full with rivals in Rome, France, and central Europe.

Sultan Suleiman in Constantinople was not slow to see this. He was the ninth sultan of the Ottoman Empire, successor to a long line of able, resourceful, daring, and strongly religious rulers. He inherited an empire that stretched from the Persian frontier in the east to Morocco in the west, as well as much of the Balkans. He also inherited a military that in its own way was as impressive as anything Charles or Francis could put in the field. The pride of the Ottoman army lay in two arms: the heavy infantry and the artillery. Since the days of the second sultan, Ala ed-Din, the Ottoman government had accepted for taxes payment in kind in the form of male children of Christian families. They became slaves, were raised as Moslems, and from their youth trained as soldiers. They developed into a fearsome unit called the Janissaries, completely dedicated to their faith and their sultan and, in the service of both, ready to go anywhere and fight any enemy. The Ottoman Turks had also learned from western Europe the craft of casting artillery, and they had far outstripped their teachers. The Ottomans produced the largest guns of their day, and with them they captured Constantinople in 1453 after it had stood unconquered for more than a thousand years. Heavy siege guns were the Turks’ specialty, and many cities became Ottoman possessions because of those weapons, just as many armies fell before the talent and élan of the Janissaries.

Although Suleiman was an open-minded and interesting political ruler whom the Europeans viewed as a man with whom they could do business, he was also caliph of all Islam, thanks to the recent acquisition of Egypt and deposition of the last spiritual leader. Suleiman was therefore bound by the tenets of his faith to spread Islam and convert the unbelievers or exact tribute from them. As such, he conducted campaigns against the Persians, and he also looked to extend his political and religious dominion into Europe. He was also contacted by the vengeful King Francis, who encouraged an invasion to threaten Charles’s eastern front and correspondingly weaken his French frontier.

Suleiman’s venture into Europe began in the summer of 1526 when he captured Buda and placed Hungary under his sway, promoting John Zapolya, governor of Transylvania, to the Hungarian throne as his tributary monarch. That throne was contested, however, by Ferdinand, archduke of Austria and king of Bohemia. While Suleiman was campaigning in Persia in 1528, a rebellion broke out in Hungary. Some of the rebellious factions claimed to be fighting for Ferdinand’s cause. Once his Persian problems were settled—at least temporarily—Suleiman made ready to march on Ferdinand’s home city of Vienna and add Austria and the Holy Roman Empire to his own Ottoman Empire.

The Battle

Suleiman led his army out of Constantinople on 10 April 1529. When Ferdinand heard of this, he called a council in Bohemia to gather an army. For the most part, his requests went unanswered. Lots of promises were made by Austria and Bohemia and the empire, but few troops actually arrived. Charles was busy with trouble in Italy and had to keep an eye on both Francis and Clement. In Vienna, meanwhile, the 250-year-old city walls, no more than 5 feet thick, were in many places badly in need of repair. They could not be mended with masonry, as there was no time, so for the most part dirt and the debris of the suburbs were used because the outlying houses were razed to open up a field of fire before the city walls. The official in charge in Vienna was Philip, count palatine of Austria. He was assisted in his job by two talented men, Graf Nicholas zu Salm-Reifferscheidt and William von Roggendorff. Graf Nicholas oversaw the wall repairs, gathered in as much food and ammunition as he could, and expelled from the city as many women and children as he could to ease the supply burden. During the siege itself, he oversaw the placement of the artillery, seventy-two guns of widely varying size and caliber. When the siege began, the city was defended by a garrison of 22,000 infantry and 2,000 cavalry. Between the garrisons that Suleiman had absorbed along his line of march, reinforcements commanded by his lackey King John Zapolya, and innumerable camp followers, the Ottoman force that stood before Vienna on 26 September 1529 was possibly as large as 150,000 people[including camp followers], although it included probably 80,000 Turkish soldiers and another 6,000 Hungarians.

The Ottoman advance had been a wonder to behold. Many of the Janissaries advanced up the Danube in boats, stopping with Suleiman for 5 days at Buda to recapture the city and massacre the defenders. News of that action, as well as the activities of some 20,000 akinji (ransackers) that were devastating the countryside all along the line of march, motivated the defenders in Vienna to fix their walls as best they could. The first contingent of Turks arrived in sight of Vienna on 23 September and skirmished with the Viennese cavalry. By 27 September, the city was surrounded, and Suleiman sent a delegation to demand its surrender. The delegation was comprised of four captured cavalrymen, fabulously dressed in Turkish clothing. The sultan stated that an immediate surrender would end in no occupation of the city but for a few functionaries, and he would have breakfast there on the morning of 29 September. Resist, and the city would be destroyed so thoroughly that no one would ever again find a trace of it. Graf Nicholas, de facto commander, sent back four richly dressed Turkish prisoners; they carried no answer at all, which was answer enough.

The fate of Vienna in reality lay neither in the city walls nor the attacking army, but in the weather. The summer of 1529 was the wettest anyone in southeastern Europe could remember, and the supply wagons, vital to supporting the immense force before Vienna, lagged far behind. Worse still for the Ottoman cause, the massive siege artillery also could not be moved along the muddy roads. The artillery that Suleiman had with him were 300 small pieces that lacked the destructive power necessary to break down even these old walls.

Suleiman’s only alternative was to mine the city walls. This involves digging a tunnel from one’s own protected trenches under the walls of the enemy and then filling the tunnel with gunpowder and exploding it. The collapsing tunnel would then collapse a section of wall. Such operations began immediately, but the defenders were lucky enough to learn the placement of the mines from a deserter. They quickly countermined, either digging their own tunnels under those being dug by the Turks in order to collapse them or digging at the same level, which resulted in underground battles, in which the defenders tended to be the more victorious. Not all of the mines could be discovered, however, and some of them worked. The breaches, which were occasionally large enough to ride several horses through abreast, could not be exploited. Behind the walls, the defenders had dug trenches and built wooden palisades from which they beat back the attackers. The breaches were held by the same stolid pikemen that had won the battles of western Europe, and the swords of the Janissaries were of little use in the cramped confines of the battle. A major battle in one breach on 12 October resulted in the Janissaries leaving behind 1,200 dead.

On the night of 12 October, Suleiman held a council of war. The supply wagons had not arrived, and the countryside was not providing nearly enough food to support his army. The city was proving unexpectedly tough. Winter was approaching. The defenders had won every encounter in the breaches that had been created, and the attackers’ death toll was between 14,000 and 20,000, primarily Janissaries and aristocratic cavalry. For the first time in their history, the Janissaries complained that they were being sacrificed. To do just that had been their duty and indeed their entire life for nearly two centuries. Suleiman offered them a huge bonus for one more attack. On 14 October, another mine blew up, but the collapsing wall fell outward, creating such a pile of rubble that it was impossible for the attackers to rush the breach. The pikemen once again stood firm in the face of the Janissary onslaught, and once again they turned the attackers away.

That night, the Ottoman army struck its tents, which had covered the plain outside Vienna for as far as the eye could see. In massive bonfires, they burned everything that they could not carry and then threw their prisoners in the flames as well. The army marched away the next morning as it snowed.

A relative handful of men saved western Europe from Ottoman invasion. At first it seemed that little had changed, however. John Zapolya still ruled in Suleiman’s name in Buda, and Hungary was part of the Ottoman domain. Although Suleiman returned 3 years later to finish the job he had started, a spirited resistance at the town of Guns (modern Koszeg, Austria)

and a major deployment of European troops under Charles V once again convinced him to return home. Another uprising in Persia diverted Suleiman’s attention, so he made peace with Ferdinand and turned his armies eastward. He returned to Europe in 1541 to recapture Hungary from Ferdinand’s invasion, but he went no farther.

Suleiman presided over the Ottoman Empire at its zenith, both in power and territory. After him, the long line of talented sultans ended. His son, Selim (called “the Sot”), had none of his father’s talents. From Selim’s rule forward the Ottoman Empire began a long decline until by the nineteenth century it was regarded by the world as “the sick man of Europe.” Had Suleiman captured Vienna, he could have wintered there and proceeded the following season to invade Germany. Any sort of cooperative moves by France would have placed the Holy Roman Empire in a vise. That would have served Francis’s aims in the short term, but he certainly overestimated his influence on the sultan. Islam could well have triumphed against a divided enemy.

Within the Ottoman military, the zenith passed as well. Vienna marked the beginning of the end for the Janissaries, for their once invincible front had been shattered. They could be beaten, and not only did their enemies know it, but so did the soldiers themselves. The bribe they were offered for that final attack was proof that their élan was no more. “The Janissaries themselves degenerated from the mighty force they had been. They used their power to improve their personal lives, at the expense of the state” (McCarthy, The Ottoman Turks, p. 164). “The Janissaries were to turn into unruly Praetorian guards, who made and unmade sultans, and this was perhaps inevitable. But even determinism must admit that Vienna started them down the long slide” (Pratt, The Battles That Changed History, p. 149). The elite force that had been the instrument of Ottoman expansion became the instrument of internal instability.

The decline in quality leadership after Suleiman was compounded by the success of the previous Ottoman line. The empire by the middle of the sixteenth century was too large to be efficiently governed by the overly centralized authority in Constantinople. Although the limits of the empire were (for the most part) as far as an army could march from Constantinople in one campaign season, that was still too large for the nature of imperial rule. Because their primary enemies at that time were the Holy Roman Empire and Persia, only two complete armies could maintain authority. To create them would mean an increase in cost and a corresponding decrease in quality, especially with the decline of the Janissaries. Thus, the Ottoman Empire could not expand its borders any farther. Conquest and booty had always been a major contributor to the economy. Over the following century, the Turks began to experience a rise in unemployment and banditry, which the weakening government could not successfully address. Unfortunately for the Ottoman Empire, Vienna spelled a change of fortune: just when a strong and visionary ruler was vital to maintain or expand the empire, the talent pool dried up.

References: Barber, Noel. The Sultans. New York: Simon & Schuster, 1973; Clot, Andre. Suleiman the Magnificent: The Man, His Life, His Epoch. Translated by Matthew J. Reisz. London: Saqui Books, 1989; McCarthy, Justin. The Ottoman Turks. New York: Longman, 1997; Parry, V. J. A History of the Ottoman Empire to 1730. Cambridge, UK: Cambridge University Press, 1976; Pratt, Fletcher. The Battles That Changed History. Garden City, NY: Doubleday, 1956.

SÜLEYMAN I (1495–1566).

Ottoman sultan during whose reign Ottoman power reached its apex. Also called Süleyman the Lawgiver (Kanûnî) or Süleyman the Magnificent. The son of Selim I, he ascended to the throne on the death of his father (1520).

His earliest acts included the rehabilitation of prisoners, exiles, and those who suffered under the harsh rule of his father. Süleyman I issued laws protecting life, property, and honor and promoting lawful administration. The principle of merit was reinforced in promotions and in appointments to administrative positions. Administrators who acted arbitrarily during the rule of his father were tried. Measures were taken to prevent injustice in the collection of taxes.

In the reign of Süleyman I, Ottoman territorial expansion reached Vienna in Central Europe and the Indian Ocean in Asia. The period was also rich in political events. The first serious incident was the rebellion of the beglerbegi of Damascus, Canberdi Ghazali, who declared the independence of Syria (1521). This rebellion was suppressed quickly. When the Hungarians refused to continue the payment of the annual tribute, Süleyman launched a military campaign against the kingdom; in August 1521, Belgrade was conquered. The next move was to the Aegean island of Rhodes, which was governed by the Knights of St. John. Conquest of this island in December 1522 secured the sea connection between İstanbul and Egypt.

Süleyman I became closely involved in European politics when the mother of the French king Francis I—who had been captured by the Holy Roman emperor, Charles V, at the Battle of Pavia (1525)—sent a letter to İstanbul asking for help in the release of her son. The Ottomans, considering an alliance with France a means of preventing Habsburg domination in Europe, attacked and defeated Hungary (Battle of Mohács, August 1526) and appointed Janos Szapolyai as a vassal king. Thus Süleyman I became able to exert direct pressure on the Habsburgs. When Charles V’s brother, Archduke Ferdinand, ruler of Austria, claiming to be the king of Hungary, occupied Buda and expelled Szapolyai, the Ottomans responded in force and reestablished him (September 1529). Süleyman, in order to discourage Ferdinand’s ambitions in Hungary, laid siege to Vienna (October 1529). The issue of Hungary led to a new war with the Habsburgs, in which Güns and Graz were besieged (1531–33).

A formal military alliance between the Ottoman Empire and France was concluded in 1536, and capitulations were granted to French merchants. As part of a joint plan to attack Charles V, French forces entered northern Italy while Ottoman forces attacked Venetian ports in the south (1537–40). A naval campaign resulted in Ottoman victory at the Battle of Preveza (1538). This gave the Ottomans the upper hand in the Mediterranean until their defeat at the Battle of Lepanto (1571).

When Szapolyai died in 1541, Ferdinand besieged Buda, and Süleyman was again forced to move against the Habsburgs. After the Austrians were pushed out, Hungary became a beglerbegilik, administered from İstanbul. During the Ottoman-Habsburg war of 1541–47, the towns of Esztergom and Stuhlweissenburg (Istolni Belgrad) were conquered (1543). Meanwhile the Ottoman navy, headed by Barbaros Hayreddin Pasha, occupied the Habsburg fortresses of Messina, Reggio, and Nice (1543). The Ottoman-Habsburg peace of 1547 stipulated the payment of an annual tribute by the Holy Roman Empire to İstanbul.

The peace of 1547 was terminated by Habsburg attempts to take control of Transylvania (1550). This move was repulsed, and the Ottomans attacked the Habsburg strongholds of Eger, Malta, and Tripolitany, conquering only the last (August 1551). At the same time, Süleyman I approached the Protestant princes of Germany and urged them to cooperate with France against the Catholic Habsburgs. By this he aimed to increase disunity among the Christians. Though a peace agreement was signed in 1562, renewed hostilities led to an (unsuccessful) Ottoman naval expedition to Malta (May–September 1565). When the Habsburgs refused to pay the annual tribute or evacuate the Transylvanian towns of Tokaj and Serencz, Süleyman I launched his last military campaign. He died during the siege of the fortress of Szigetvar (September 1566).

Ottoman engagements in the East during the reign of Süleyman I aimed at preventing the extension of the Shia influence of Safavid Iran in Anatolia and at expanding Ottoman domination over Islamic countries. A military campaign against Iran of 1533–35 resulted in the conquests of Tabriz (Azerbaijan) and Baghdad (Iraq). When the brother of the Safavid Shah Tahmasb I, Elkas Mirza, revolted against Iran and took refuge with the Ottomans, Süleyman used this opportunity to begin a second campaign against the Safavids (1548–55). During this war, Van (eastern Anatolia) and Azerbaijan were reconquered, and Georgia was annexed. These acquisitions were ratified by the Ottoman-Iranian peace Treaty of Amasya (May 1555).

Süleyman I’s reign witnessed the extension of an Ottoman naval presence from the western Mediterranean to eastern Africa and the western coasts of India. When Barbaros Hayreddin Pasha left Algiers to Ottoman rule (1533), the western Mediterranean entered the Ottoman area of naval activity. The governor of Egypt, Hadım Süleyman Pasha, led the Ottoman Red Sea fleet toward the south and conquered Aden (Yemen) but was unable to take the fortress of Diu (Gujarat, India) from the Portuguese (1538). After Basra (in Iraq) came under Ottoman rule (1538), Suez and Basra became the main Ottoman naval bases for operations in the Indian Ocean.

During the rule of Süleyman I, Ottoman civilization produced its major classics in art and literature. Poets like Bâkî and Fuzulî; prose authors like Celâlzâde Mustafa Çelebi, Kınalızâde Ali Çelebi, Latifî, Lutfî Pasha, Sehî Bey, and Taşköprülüzâde İsameddin Ahmed; jurists like Ebussuud Efendi; and architects like Mimar Sinan produced their works in these decades. At the same time, signs of institutional decline were to be observed toward the end of Süleyman’s life.


Contacts between the Germans, in the general sense, and the Ottomans dates back probably to the battle of Nikopolis (1396). The Habsburg Empire and the Ottomans, as neighboring powers, confronted each other following the Ottoman occupation of Hungary (1526). Janos Szapolyai, who was appointed by Süleyman I as the new king of Hungary, was attacked and expelled by Ferdinand I. This development triggered an Ottoman expedition in 1529 against the Habsburgs to restore Szapolyai; Vienna was besieged for the first time. In 1533 a peace was made, by which Ferdinand I acknowledged Ottoman suzerainty. Warfare continued between the Habsburg Empire and the Ottomans, in which the latter were dominant until the wars between 1593 and 1606. The Treaty of Zsitvatorok (1606) terminated the Austrian vassalage.

The new military superiority of the Habsburg Empire over the Ottomans was marked by the period following the second Siege of Vienna (1683). The warfare between the Holy League and the Ottomans between 1683 and 1699 proved to be disastrous for the latter. By the Treaty of Karlowitz (1699) the Ottomans had to abandon Hungary, Croatia, and their suzerainty over Transylvania to the Habsburgs. After 1699 the Ottomans entered into a state of constant defensive warfare against the Austrians. The Habsburg Empire, collaborating with Russia and Venice, tried to penetrate deeper into the Balkans. The result of the war of 1714–18 was the loss of northern Serbia, including Belgrade, and Temesvar, to Austria (Treaty of Passarowitz, 1718). The Ottomans were able to regain Belgrade and Temesvar during another war, 1736–39 (Treaty of Belgrade, 1739). The last major war between the Habsburg Empire and the Ottomans took place between 1788 and 1791; the ensuing Peace of Sistova (Ziştovi) did not alter the borders.

During the 19th century the Habsburg Empire continued to increase its political influence in the Ottoman Empire, with a view to domination in the Balkans. In order to attain this goal, Austria presented itself as the protector of the interests of the Balkan Catholics—that is, Albanian Catholics. The increasing rivalry between the Habsburg Empire and Russia in the Balkans and the interest of the latter in the Balkan Slavic nationalist movements led the Austrians to support Albanian nationalism. The Russo-Ottoman War of 1877–1878 and the Congress of Berlin secured the Austrian occupation of Bosnia and Herzegovina, formally annexed in 1908. During World War I the Habsburg Empire and the Ottomans were allied.


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