Siege of Vienna (1529): Suleiman's First Attempt on Vienna

The Siege of Vienna in 1529 was the first Ottoman attempt to capture the capital of the Habsburg lands in Central Europe. From late September to mid-October 1529, the army of Sultan Suleiman the Magnificent besieged the city, but its garrison under Count Niklas Salm beat off every assault. The Ottoman withdrawal marked the furthest point of Suleiman’s advance into Europe and set the frontier between the two empires for a generation.

Background

The siege grew out of the struggle for Hungary that followed the Battle of Mohács in 1526, where the Ottomans destroyed the Hungarian army and King Louis II died. Two rival kings were elected in his place: John Zápolya, the leading Hungarian magnate, and Ferdinand of Habsburg, Archduke of Austria and brother of Emperor Charles V.

In 1527 Ferdinand defeated Zápolya and took Buda, the Hungarian capital. Zápolya fled to Poland and appealed to Suleiman. In 1528 the sultan accepted him as a vassal and promised to restore him. For Suleiman, Ferdinand’s claims to Hungary were a direct challenge, and the Habsburgs were his main rivals in Europe.

The broader situation favoured an Ottoman campaign. Charles V was still occupied with wars against France in Italy and with the religious divisions caused by the Reformation in Germany. Ferdinand had few troops and little money of his own.

The march on Vienna

Suleiman left Constantinople on 10 May 1529 with a very large army, often estimated at 100,000–120,000 men, though many of them were support troops rather than combat soldiers. The grand vizier Pargalı Ibrahim Pasha served as commander-in-chief.

That spring and summer were exceptionally wet. Rain turned roads into mud and swelled the rivers of the Balkans, and the army fell weeks behind schedule. Many camels and pack animals died, and the Ottomans had to leave most of their heavy siege artillery behind, bringing mainly lighter guns.

On the field of Mohács in August, John Zápolya came to pay homage to the sultan. The army then advanced to Buda, which surrendered in early September after a short siege, and Zápolya was restored there. Suleiman moved on up the Danube, taking smaller towns, while light cavalry raiders, the akıncı, spread far into Lower Austria, burning villages and taking captives.

Preparing the defence

Ferdinand himself remained outside the city, gathering troops and seeking help from the princes of the Holy Roman Empire. Command in Vienna was given to Count Niklas Salm, a veteran of about 70 who had fought at Pavia in 1525, alongside the marshal Wilhelm von Roggendorf.

Vienna’s medieval walls were old and relatively thin. Salm worked quickly to strengthen them. Gates were walled up except for the essential ones, an earth rampart was raised behind the walls, and houses and suburbs outside the walls were demolished to clear lines of fire. Paving stones were taken up inside the city to reduce the effect of cannon balls.

The garrison numbered roughly 17,000–23,000 men. Most were German landsknechts and Austrian troops, with a contingent of Spanish arquebusiers under Luis de Ávalos and armed citizens. Reinforcements had reached the city shortly before the Ottomans arrived.

The siege

The Ottoman vanguard appeared before Vienna in the last days of September, and by 27 September the city was surrounded. The great Ottoman camp spread across the surrounding villages, with Suleiman’s tent at Simmering, south-east of the city.

Without heavy guns, the attackers depended on mining. Ottoman sappers dug tunnels towards the walls to place gunpowder charges, especially near the Kärntnertor, the Carinthian Gate, on the south side. The defenders listened for the diggers, sometimes using bowls of water or drums with dried peas that trembled at the vibrations, and dug countermines to break into the tunnels. Bitter fighting took place underground.

Several mines exploded and opened breaches in the walls. On 9, 11 and 12 October the Ottomans launched major assaults through the gaps, but each time the landsknechts and Spaniards drove them back with heavy losses. The defenders also made sorties against Ottoman positions, with mixed results.

Why the Ottomans withdrew

By mid-October conditions in the Ottoman camp were worsening. Supplies were running short, the weather was turning cold, and the Janissaries were unhappy at the prospect of a winter campaign far from home. The sultan’s armies were traditionally expected to return to winter quarters by late autumn.

A final assault on 14 October also failed. On the night of 14–15 October the Ottomans burned their camp and began to withdraw. Contemporary Christian reports say that many prisoners were killed before the departure. Early snow fell during the retreat, and the army suffered further losses on the long march back.

Count Salm had been seriously wounded during the defence, reportedly by debris from a mine explosion. He died of his injuries in 1530.

What were Suleiman’s aims?

Historians disagree about how far Suleiman intended to conquer Vienna. Some argue that the city was a real target and that its capture would have opened the way into southern Germany. Others stress that the declared purpose of the campaign was to restore Zápolya and to force Ferdinand to battle, and that taking Vienna was a hoped-for bonus rather than the core objective.

Either way, the late start of the campaign was decisive. An army that left Constantinople in May and only reached Vienna at the end of September had very little time before winter, whatever its intentions.

Key people

• Suleiman the Magnificent (1494–1566): Ottoman sultan who led the campaign in person.
• Niklas Graf Salm (1459–1530): commander of the defence of Vienna, who died of wounds received during the siege.
• Ferdinand I (1503–1564): Archduke of Austria and rival King of Hungary, later Holy Roman Emperor.
• Pargalı Ibrahim Pasha (c. 1495–1536): grand vizier and Ottoman commander-in-chief.
• John Zápolya (1487–1540): King of Hungary as Suleiman’s vassal, whose cause was the occasion for the campaign.

Consequences

The siege did not change the political map at once. Zápolya remained king in Buda under Ottoman protection, while Ferdinand held the west and north of Hungary. In 1532 Suleiman launched a new campaign but was delayed for weeks by the small fortress of Kőszeg (Güns), defended by Nikola Jurišić, and did not reach Vienna. A truce in 1533 recognised the divided situation.

After Zápolya’s death in 1540, the Ottomans occupied Buda in 1541 and annexed central Hungary. The frontier between the Habsburg and Ottoman empires then ran through Hungary for about 150 years, with constant border warfare.

The threat also shaped European diplomacy. France, seeking allies against Charles V, moved closer to the Ottomans, leading to the Franco-Ottoman alliance of the 1530s. In Germany the Ottoman danger made Charles V more willing to compromise with the Protestant princes, whose troops he needed.

In Austria and southern Germany the raids of 1529 left a lasting memory. Contemporary pamphlets, woodcuts and songs described the devastation of the countryside and the fate of captives, and helped spread an image of the “Turk” as the great enemy of Christendom that would shape European attitudes for generations.

Myths and facts

Myth: The siege was a crushing Ottoman defeat. There was no great battle, and the Ottoman army withdrew largely intact. Ottoman court histories presented the campaign as a success, since Zápolya was restored and Ferdinand’s army never dared to face the sultan in the field.

Myth: The croissant was invented to celebrate the Turkish defeat at Vienna. This story is usually attached to the 1683 siege and has no reliable historical basis; the croissant as we know it developed much later in France.

Fact: Vienna’s survival was not certain. Several breaches were opened, and contemporaries believed the city could easily have fallen had the siege started earlier or the Ottomans brought their heavy guns.

By the numbers

Timeline

• 1526, 29 August: Battle of Mohács; Louis II of Hungary dies.
• 1527: Ferdinand drives John Zápolya out of Buda.
• 1529, 10 May: Suleiman leaves Constantinople.
• 1529, August: Zápolya pays homage to Suleiman at Mohács.
• 1529, early September: Buda falls and Zápolya is restored.
• 1529, 27 September: Vienna is fully surrounded.
• 1529, 9–12 October: Repeated Ottoman assaults through mine breaches are repulsed.
• 1529, 14 October: The final assault fails.
• 1529, 15 October: The Ottoman army begins its retreat.
• 1532, August: The siege of Kőszeg halts a second Ottoman advance.

Legacy

The siege made Vienna a symbol of Christian Europe’s resistance to the Ottomans, an image reinforced after the Battle of Vienna in 1683. In the decades after 1529 the city’s medieval walls were replaced with modern bastioned fortifications in the Italian style, which helped it withstand the second siege more than 150 years later.

Count Salm became a local hero. His tomb, made in the 1530s, was later moved to the Votivkirche, the neo-Gothic church built in the 19th century, where it can still be seen.

Why it matters

The first Siege of Vienna marked the limit of Ottoman expansion into Central Europe under Suleiman the Magnificent. It confirmed the long rivalry between Habsburgs and Ottomans in Hungary and showed that even the greatest army of the age was bound by distance, weather and the length of the campaigning season.