Understanding The First Ottoman Siege Of Vienna – The Siege That Seized Ottoman Advances

Gateway to the West: The Siege of Vienna in 1529

The First Ottoman Siege of Vienna took place in 1529 during the Ottoman War in Europe. It was a turning point in the tide of Ottoman advance in Europe, and its origins lay in the Hungarian Civil War. Ottoman Sultan Suleiman had his sights on Vienna to establish control over Central Europe. The siege was both a military campaign and the culmination of diplomatic and imperial rivalries over Hungary.

The city of Vienna became a symbolic focal point in a conflict over territorial claims and imperial ambitions. The defending city of Vienna faced not just an assault but the preservation of the Western European cultural, religious, and political identity. The Siege of Vienna would be set against the machinations of alliance politics and military technologies of its time.

Prelude to the Siege: Ottoman Ambitions and European Politics

The background to the 1529 Siege of Vienna was established over the previous decades. In the wake of the Battle of Mohács in 1526, where the Ottomans under Sultan Suleiman I crushed the Hungarians under King Louis II, the Hungarian king died, leaving a power vacuum.

This led to the partition of the country between the Archduke Ferdinand I of Austria and the Hungarian nobleman John Zápolya of Transylvania. The former won the western part of the country with the backing of the Holy Roman Empire, while the latter had allied himself with the Ottomans. Zápolya became Suleiman’s vassal in exchange for the sultan recognizing him as the king of the eastern part of Hungary and Transylvania.

This new status quo divided Hungary into Royal, Ottoman, and Transylvanian spheres that soon led to a power struggle that would eventually involve Vienna as well. A determined Ottoman reaction put an end to Ferdinand’s plans to take all of Hungary. A powerful Ottoman counterattack negated his temporary capture of Buda in 1527 and demonstrated that Suleiman would not relinquish his influence in the region. The new power balance in Eastern Europe showed that the Ottoman Empire had no intention of abandoning the territories that it had acquired and sought to expand further into central Europe.

By spring 1529, Suleiman was set to launch an even bolder campaign aimed at further solidifying Ottoman rule over all of Hungary and placing the European powers in confrontation with the Ottoman state.

He gathered what was one of the largest Ottoman forces ever mustered, with reports of up to 300,000 troops, including many Sipahi cavalrymen and janissaries. The size of the army alone and the commitment of forces from across the Ottoman state were a clear indication of the importance of this campaign. 

On the other hand, logistical issues of transporting an army of this size and heavy artillery support through the Balkans were no easy task. Springtime conditions in the region were harsh, with heavy rainfalls that caused some of the heaviest losses throughout the campaign, but Suleiman was not one to shy away from such a challenge.

As the Ottomans continued their march westward, they retook some of the lost ground, including the vital Buda, firmly reestablishing Suleiman’s control over Hungary. The grand army, with the full might of the Empire behind it, began its march on Vienna. 

The following siege became a turning point, a real test of both the Holy Roman Empire and Suleiman the Magnificent, the Ottoman sultan. The siege of Vienna marked a significant milestone in a centuries-long battle for supremacy between the Ottoman state and European powers. This attempt by the Ottoman Empire to seize such an important European center was not just an act of military aggression but a direct claim to the larger European lands, with dire consequences both in the East and the West.

Vienna’s Defense: A Multinational Effort

As the Ottomans neared Vienna in 1529, they prepared to withstand a siege. Vienna was on alert as the massive Ottoman force was approaching the city. The city, while partially defended by a local militia of farmers and peasants, also had an army of European mercenaries. The defenders of the city included 1,000 German Landsknechts under Count Niklas Salm, as well as 700–800 Spanish harquebusiers under Marshal Luis de Ávalos. These light cavalry units were important in establishing Vienna’s defenses, being particularly adept at using fortifications and ranged weapons in battle.

The overall organization of Vienna’s defense was the responsibility of Wilhelm von Roggendorf, the Hofmeister of Austria. However, Count Nicholas of Salm, the Hofmeister of Lower Austria, who was at the Battle of Pavia three years earlier, led the defenders. Salm established positions in the area around the city’s landmark St. Stephen’s Cathedral, which became his headquarters. The old city walls, in places only in thickness, were rapidly reinforced, and earthen bastions were constructed. The city’s gates were also strengthened in anticipation of the Ottoman artillery.

The construction of palisades and trap pits indicates a high level of military training and experience among the defenders. The Ottoman forces had not been able to position their troops close to the walls and, in particular, to the Danube meadows, which offered an excellent vantage point from which to launch a concerted attack.

The Siege Begins: Challenges and Initial Confrontations

As the Ottomans completed their encampment outside of Vienna at the end of September 1529, their numbers had been drastically reduced by the journey across the Balkans and the brutal weather they had experienced. Though still massive and powerful, Suleiman’s forces were not without logistical problems: the supply lines into the city were tenuous at best, and the siege train in particular was short of key components, including camels and large siege guns. Also, a large number of the troops were in less-than-ideal condition, having just completed an arduous, wet-season march across the Balkans.

The initial efforts to storm the city involved few direct military engagements; instead, they were posturing tactics. Suleiman sent three well-dressed Austrian prisoners to Vienna, demanding that the city surrender to him or face a siege, a clear signal of his desire for a peaceful resolution to the campaign. Count Nicholas of Salm, the commander of Vienna’s garrison, decided that he would communicate in the same manner, but refused to directly answer the message. Sending back three similarly dressed Muslim prisoners, Salm made it very clear that he was in no mood to negotiate. The resolve of the Viennese citizens not to surrender was set.

Attacks on the city’s walls were initiated almost immediately, with Ottoman sappers tunneling beneath the walls to attempt to undermine the fortifications. Defenders of Vienna frequently sortied from the walls to keep watch over these operations, causing some of the tunnels to collapse, and claiming many casualties from those mining beneath. The largest of these occurred on October 6, when 8,000 defenders were sent out against the Ottoman sappers to slow or destroy their tunneling operations.

This particular sortie was successful in temporarily halting the Ottoman mining operations, as the defending troops systematically destroyed the tunnels. However, the sortie was a costly affair for the Austrians, as the close quarters of the underground tunnels and the inability to retreat to the relative safety of the walls without being detected led to their near-total annihilation.

By mid-October, the siege of Vienna had reached a critical point. The prolonged rain had not only further depressed the morale of the Ottoman troops, but it was now also impeding the actual siege operation. With food and water supplies running low and the soldiers’ condition still declining, Suleiman was under increasing pressure from the janissaries and the rest of the army to make a decision.

Morale and the willingness to continue the siege, in the face of the defenders’ continued resistance, continued to decline as the days passed with no significant progress. By October 12, Sultan Suleiman called his council to discuss whether they should advance further or retreat. The strain of the long siege was becoming apparent, with tactics and morale both at a low.

The Final Stand and Retreat from Vienna

Suleiman now saw a final all-out attack as his last chance to take the city before it was too late. On October 14, with his men pressed by winter’s onset and their food supplies diminishing, he ordered the Ottomans to prepare for a full-on “all or nothing” attack on the city. The sultan promised his men a generous reward for their brave actions in taking Vienna. The Ottomans charged the walls, but the well-fortified city was too strong, and the troops of Vienna, equipped with arquebuses and long pikes to match the firepower and determination of the Ottoman soldiers, soundly defeated the attack.

The repulsion of the final major Ottoman attack convinced Suleiman that any further waiting or offensive action was pointless. By October 15, his army exhausted and the winter season now fully upon him, the sultan ordered a complete withdrawal back to Constantinople. He could not see the viability of remaining where they were under the adverse conditions and ordered a strategic withdrawal back to Constantinople, both physically and strategically, from the battle for Vienna and from the continued attempts to take over Europe.

The march back to Constantinople was not easy. Early snow and bitter cold did not help matters. The roads, now turned to mud, slowed the travel of horses and camels. The Ottomans were on the move, but the Austrians, in an opportunistic attempt, launched repeated raids, capturing a large number of stragglers from the central Ottoman forces. However, the Austrian army, while opportunistic in their counterattacks, did not launch a full-scale counterattack against the retreating Ottoman army. The Ottomans returned to Buda on October 26 and to Belgrade on November 10. It was not until December 16 that the Ottomans returned to Constantinople to end the campaign.

Repercussions of the First Siege of Vienna

For the Ottomans, the failed siege was still a costly affair, resulting in the loss of approximately 1,500 soldiers, a major portion of the city’s overall defense force. The siege of Vienna also marked a turning point for the Austrians of Vienna, who, while managing to ward off the invaders this time, fully comprehended the precarious position of their city and its importance in the conflict with the Ottomans. The need for an effective defense system and additional military measures to protect Vienna from further Ottoman attempts to capture the city became evident to them after the siege.

The siege of Vienna also had profound long-term consequences. It made the European states wake up to the growing Ottoman threat and work more cohesively in their military campaigns against the Ottomans. In addition, the besieged city’s defense system and its defenders impressed Europe with their tenacity, and its mighty fortress successfully repulsed the Ottoman army.

In the event, the Ottomans lost about 15,000 soldiers during the siege, killed, wounded, or taken prisoner. Although they had failed to take Vienna, they had inflicted considerable damage on the city and its defenses, which was likely part of a long-term Ottoman strategy. Sultan Suleiman had decided to weaken Vienna, a major bulwark against further Ottoman expansion in Europe, thereby making it vulnerable to a future attack.

This strategy had similar roots to his attack on Buda in 1526, and he planned to return to Vienna in the spring of 1532 for another attack. However, the campaign never came to fruition because of the stiff defense by Croatian Captain Nikola Jurišić at Güns (Kőszeg). Nikola Jurišić and a small force of between 700 and 800 men succeeded in holding the Ottoman army at bay until the winter set in, forcing it to retreat and leaving it to pillage and burn Styria as it went.

The failure of the siege also had significant diplomatic consequences, as Charles V and Pope Clement VII settled longstanding grievances, leading to the Pope’s coronation of Charles as Holy Roman Emperor in 1530. On the other hand, the Ottomans, by advertising the campaign as a strategic victory, further aggrandized their imperial image through grandiose ceremonies in Istanbul and increased their influence in Hungary by relying on their vassal, John Zápolya.

However, Vienna would still be a jewel that the Ottomans would desperately yearn to take from Christian Europe, as witnessed by the 1683 Siege of Vienna.