The Siege of Vienna — Imperial Ottoman

The city of Vienna was besieged twice by the armies of the Ottoman Empire: in 1529, by the army of Suleiman the Magnificent, and in 1683, by the army of Grand Vizier Kara Mustafa Pasha under Sultan Mehmed IV. The two sieges are the most celebrated military operations in the long history of the Ottoman-Habsburg wars, and they are conventionally treated as the high-water mark and the turning point of Ottoman expansion into central Europe. The wider context is in the Ottoman military and warfare pillar and in the article on Ottoman gunpowder siege warfare.

Key dates

29 August 1526 — Battle of Mohács; the Hungarian kingdom is broken.
27 September 1529 — The Ottoman army arrives before the walls of Vienna.
14 October 1529 — The first siege is lifted; Suleiman retreats south.
1683 — Kara Mustafa Pasha’s army invades Austria in early July.
12 September 1683 — Sobieski’s charge up the Kahlenberg; the second siege is broken.
25 December 1683 — Kara Mustafa Pasha is executed in Belgrade.
26 January 1699 — Treaty of Karlowitz; first major Ottoman cession of territory.

The strategic context

Vienna, the seat of the Habsburg dynasty and the capital of the Holy Roman Empire’s eastern lands, was the principal Christian stronghold on the Ottoman-Habsburg frontier. The city had been threatened by the Ottomans from the late fourteenth century, and the long Hungarian wars of the fifteenth and sixteenth centuries had brought the Ottoman army to the gates of Vienna on several occasions. The fall of Belgrade in 1521 and the victory at Mohács in 1526 had opened the way for the first siege; the long war of 1663–1664 and the revolt of Imre Thököly in 1682–83 had opened the way for the second.

The first siege, 1529

The first siege of Vienna was the climactic operation of the early reign of Suleiman the Magnificent. The Ottoman army, numbering perhaps 80,000 to 100,000 men, with a strong contingent of Janissaries and a substantial artillery train, marched into Austria in the early autumn of 1529. The army was supported by the Tatar cavalry of the Crimean khan, and the army of John Zápolya, the rival Hungarian king supported by the Ottomans. The Habsburg garrison, under the command of the Austrian general Count Niklas Graf Salm, numbered perhaps 17,000 men, of whom only some 5,000 were regular soldiers.

The Ottoman army arrived before the walls of Vienna on 27 September 1529 and began the siege. The assault was marked by the heavy bombardment of the walls, by a series of mining operations, and by a number of massed assaults on the gates and the breaches. The defence was tenacious, and the garrison, supported by the burghers of the city, held the walls for nearly three weeks. The approach of an imperial relief force under Philip, Elector Palatine, supported by Georg von Frundsberg and the Swabian League — together with the worsening weather, the early onset of winter, and the dwindling Ottoman supply lines — forced Suleiman to lift the siege on 14 October 1529. Salm, who had been gravely wounded during the siege, died of his wounds in May 1530. The Ottoman army retreated to the south, and the city was saved.

The first siege of Vienna was, in the long run, a setback for the Ottoman position in central Europe. The failure to take the city, combined with the long Hungarian war and the eventual execution of the Ottoman grand vizier Ibrahim Pasha in March 1536 at Suleiman’s order, marked a turning point in the reign of Suleiman. The siege did not, however, mark the end of the Ottoman threat: the Ottomans returned to Hungary in 1541, taking Buda and Pest, and the long contest with the Habsburgs continued for another century and a half.

The second siege, 1683

The second siege of Vienna was the climactic operation of the long war of 1683. The Ottoman army, under Grand Vizier Kara Mustafa Pasha, marched into Austria in the summer of 1683, supported by the Tatar cavalry of the Crimean khan, the troops of the Transylvanian prince Imre Thököly, and the contingents of several Moldavian and Wallachian princes. The army numbered perhaps 150,000 to 200,000 men, with a strong Janissary corps, a substantial artillery train, and a powerful cavalry arm. The Habsburg garrison, under the command of the Austrian general Ernst Rüdiger von Starhemberg, numbered perhaps 20,000 men.

Kara Mustafa Pasha’s army closed on Vienna in early July 1683 and began the siege. The first weeks saw the burning of the Leopoldstadt suburb across the Danube, the construction of Kara Mustafa’s pontoon bridge — known as the Pasha’s Bridge, near today’s Rösch bridgehead — and the opening of a heavy bombardment that, by late August, had opened a practicable breach in the walls near the Burg bastion. The mines and countermines of the Ottomans and the defenders fought a long underground battle. Starhemberg’s garrison held on, in growing desperation, while the relief army gathered.

The Ottoman siege lines were not uniform. To the west and south of the city, along the slopes of the Wienerwald, the lines ran up to the hill of the Kahlenberg, the last high ground before the Danube. The arrival of the relief army under King John III Sobieski of Poland, supported by Charles V, Duke of Lorraine, and the imperial forces of Emperor Leopold I, decided the campaign. On 12 September 1683, Sobieski led the famous charge of the Polish winged hussars up the slopes of the Kahlenberg into the Ottoman left wing, while Lorraine attacked the centre. The Ottoman line, weakened by the relief assault and shaken by the sudden collapse of the Tatar cavalry, broke. Kara Mustafa Pasha withdrew with the remnant of his army, and the siege was lifted. Kara Mustafa himself was executed in Belgrade on 25 December 1683, on the order of Sultan Mehmed IV, in recognition of the scale of the disaster.

Naima, the Ottoman court chronicler of the late seventeenth and early eighteenth centuries, recorded the court’s reading of the defeat:

“The empire’s arm was broken at Vienna. The army which had been gathered from Rumelia and Anatolia returned scattered to its provinces, and the treasury of the sultan was emptied. The great men of the state looked one upon another, and none could say when the loss would be made good.” — Naima, Tarih (early 18th c.).

The aftermath

The two sieges of Vienna are conventionally treated as the high-water mark and the turning point of Ottoman expansion into central Europe. The first siege, in 1529, marked the limit of Ottoman ambitions in the region; the second, in 1683, marked the beginning of the long Ottoman retreat. The Treaty of Karlowitz of 26 January 1699, by which the Ottomans ceded Hungary, Transylvania, and parts of the Morea to the Habsburgs, Podolia to Poland, and Azov to Russia, was the first major territorial settlement the empire had ever been compelled to accept in a peace treaty.

The sieges are also important in the history of the Ottoman military. The first siege of 1529 was a high point of the classical Ottoman army, the army of the Janissaries, the sipahi cavalry, and the great bombards. The second siege of 1683 was the last great operation of that army, and the failure of the siege was widely attributed, in part, to the decline of the Janissary corps and the long erosion of the timar system. Modern scholars are split on whether the 1683 failure at Vienna was the inflection point of Ottoman decline or merely a symptom of structural problems visible from the 1650s; İnalcık leans toward the former, Finkel and Rogan toward the latter.

Frequently asked questions

Who won the 1529 siege?

The Habsburg garrison under Count Niklas Salm, supported by the burghers of Vienna. The relief army under Philip, Elector Palatine, did not in fact reach the city, but the approach of imperial forces, the autumn weather, and the failure of the assault persuaded Suleiman to withdraw on 14 October 1529.

Who won the 1683 siege?

The relieving army under King John III Sobieski of Poland, supported by Charles of Lorraine. The Polish charge up the slopes of the Kahlenberg on 12 September 1683, the largest cavalry charge in the pre-modern period, broke the Ottoman line and lifted the siege.

Why did the Ottomans fail in 1683?

Three reasons are usually given: the failure of the Tatar cavalry under Khan Selim I Giray to ride down the relief army in the open ground west of the city; the late opening of the breach in the Burg bastion, which gave Starhemberg time to rebuild his wall; and the sheer scale of Kara Mustafa’s commitments, from Hungary to the Morea, which left him without strategic reserve.

Ottoman military and warfare — A general account of the Ottoman military, of which the two sieges of Vienna are the most celebrated operations.
Ottoman gunpowder siege warfare — The history of Ottoman siege warfare, of which the two sieges of Vienna are the most famous examples.
The Janissary corps — The elite infantry that formed the storm troops of the Ottoman army in both sieges.
The provincial sipahi cavalry — The timariot horsemen who fought in both sieges, and whose system was breaking down in the seventeenth century.
The Great Siege of Malta — The 1565 siege of Malta, the other great operation of Ottoman siege warfare in this period.

Sources and further reading

Rhoads Murphey, Ottoman Warfare 1500–1700 (Hurst, 1999).
Caroline Finkel, Osman’s Dream: The Story of the Ottoman Empire 1300–1923 (Basic Books, 2005).
Mesut Uyar and Edward J. Erickson, A Military History of the Ottomans: From Osman to Atatürk (Praeger, 2009).
John Keegan, A History of Warfare (Knopf, 1993).
Roger Crowley, Constantinople: The Last Great Siege, 1453 (Faber, 2005).