Siege of Güns The Siege of Güns or Siege of Kőszeg ( ) was a siege of Kőszeg ( ) in the Kingdom of Hungary within Habsburg Monarchy , that took place in 1532 . In the siege , the defending forces of the Austrian Habsburg Monarchy under the leadership of Croatian Captain Nikola Jurišić ( ) , defended the small border fort of Kőszeg with only 700 - 800 Croatian soldiers , with no cannons and few guns . The defenders prevented the advance of the Ottoman army of 120 , 000 - 200 , 000 toward Vienna , under the leadership of Sultan Suleiman the Magnificent ( " Süleymān " ) and Pargalı Ibrahim Pasha . The exact outcome is unknown , since it has two versions which differ depending on the source . In the first version Nikola Jurišić rejected the offer to surrender on favourable terms , and in the second version , the city was offered terms for a nominal surrender . Suleiman , having been delayed nearly four weeks , withdrew at the arrival of the August rains , and did not continue towards Vienna as he ' d intended , but turned homeward . Suleiman secured his possession in Hungary by conquering several other forts , but after the Ottoman withdrawal , Habsburg Emperor Ferdinand I reoccupied some of the devastated territory . Following this , Suleiman and Ferdinand concluded a 1533 treaty in Constantinople that confirmed the right of John Zápolya as a king of all Hungary , but recognised Ferdinand ' s possession of some of the reoccupied territory . Background . On August 29 , 1526 , at the Battle of Mohács , the Christian forces led by King Louis II were defeated by Ottoman forces led by Sultan Suleiman the Magnificent . Louis was killed in the battle , which resulted in the end of the independent Kingdom of Hungary as he died without an heir . Both the Kingdoms of Hungary and Croatia became disputed territories with claims from both the Habsburg and Ottoman empires . Habsburg Emperor Ferdinand I , who was a brother of Holy Roman Emperor Charles V , married the sister of Louis II and was elected King by the nobles of both Hungary and Croatia . The throne of Hungary became the subject of a dynastic dispute between Ferdinand and John Zápolya from Transylvania , since Suleiman had promised to make Zápolya the ruler of all Hungary . During Hungarian campaign of 1527 – 1528 , Ferdinand captured Buda from John Zápolya in 1527 , only to relinquish his hold on it in 1529 when an Ottoman counter - attack stripped Ferdinand of all his territorial gains during 1527 and 1528 . The siege of Vienna in 1529 was the first attempt by Suleiman the Magnificent to capture the Austrian capital . This siege signalled the pinnacle of Ottoman power and the maximum extent of Ottoman expansion in central Europe . Little War in Hungary . Following Suleiman ' s unsuccessful Siege of Vienna in 1529 , Ferdinand launched a counter - attack in 1530 to regain the initiative and avenge the destruction brought by Suleiman ' s 120 , 000 strong army . This campaign is usually considered as the start of the Little War , the period of a series conflicts between the Habsburgs and the Ottoman Empire . An assault of Buda was driven off by John Zápolya , the vassal King of Hungary , but Ferdinand was successful elsewhere , capturing Gran ( Esztergom ) and other forts along the Danube river , a vital strategic frontier . Campaign of 1532 . During the early period of the Little War in Hungary , Suleiman , as a response to Ferdinand ' s counter - attack in 1530 , and as a part of his fifth imperial campaign ( , " Sefer - i humāyūn " ) in 1532 , led a massive army of over 120 , 000 troops to besiege Vienna again . Due to Suleiman ' s rapid advances , Ferdinand feared the Christian forces would not be assembled in time to meet him . On 12 July , Suleiman wrote to Ferdinand from Osijek ( ) in Slavonia , to assure him of the Ottoman advance . According to the letter , Suleiman ' s fifth campaign was primarily directed against Charles V , and not personally against Ferdinand . After Suleiman crossed the river Drava at Osijek , instead of taking the usual route for Vienna , he turned westwards into Ferdinand ' s held Hungarian territory . According to historian Andrew Wheatcroft , on the route for Vienna , the Ottoman army had briefly invested and captured seventeen fortified towns or castles . Ferdinand withdrew his army , leaving only 700 men with no cannons and a few guns to defend Kőszeg . Siege . Located south of Sopron , the small town of Kőszeg was only a few miles from the Austrian border . It was held by a task force commanded by the Croatian soldier and diplomat Nikola Jurišić . Kőszeg was not considered a place of importance . It was an insubstantial obstacle and many stronger places had yielded without a fight . The Grand Vizier of the Ottomans , Ibrahim Pasha , did not realize how poorly defended Kőszeg was . After taking a few minor places , Suleiman came to join Ibrahim Pasha shortly afterwards , when the siege had already started . The Ottomans met stiff resistance at Kőszeg . Suleiman had hoped that the imperial army would come to relieve Kőszeg , affording him an opportunity for a larger engagement . However , during the Ottoman attacks on Kőszeg , the imperial army still formed up in Regensburg . The Ottomans continued with one attack after another ; artillery fire brought down parts of the walls , but brought no surrender . The Ottomans ' mines were sapped by countermines . The layout of Kőszeg ' s walls made mining a feasible strategy , but even though several mines succeeded in blowing holes in the fortifications , the defenders held out . For more than twenty - five days , without any artillery , Captain Nikola Jurišić and his garrison of 800 Croats held out against nineteen full - scale assaults and an incessant bombardment by the Ottomans . The outcome has two versions . In the first version , Nikola Jurišić rejected the offer to surrender on favourable terms , and the Ottomans retreated . In the second version , the city was offered terms for a nominal surrender . The only Ottomans who would be allowed to enter the castle would be a token force who would raise the Ottoman flag . In either case , Suleiman withdrew at the arrival of the August rains , and returned homeward instead of continuing towards Vienna as previously planned . He had been delayed nearly four weeks , and during this time a powerful army had been collected in Vienna , which Suleiman had not the intention to face . According to historian Paolo Giovio , Charles arrived with an imperial army at Vienna on September 23 , too late for fighting the Ottomans since Suleiman already withdrew . By their defense of Kőszeg , Nikola Jurišić and his men had saved Vienna from a siege . Aftermath . Although he was stopped at Kőszeg and failed to conquer Vienna , Suleiman additionally secured his possession in Hungary by conquering several forts , since Ferdinand and Charles evaded an open field battle . Immediately after the Ottoman withdraw , Ferdinand reoccupied devastated territory in Austria and Hungary . Nevertheless , Suleiman concluded a peace treaty with Ferdinand in 1533 , in Constantinople . The treaty confirmed the right of John Zápolya as a king of all Hungary , but recognised Ferdinand ' s possession of that part of the country that enjoyed the status quo . This treaty did not satisfy Zápolya or Ferdinand , whose armies began to skirmish along the borders . After Zápolya ' s death in 1540 , Suleiman annexed Hungary to the Ottoman realm . Although from 1529 to 1566 the borders of the Ottoman Empire moved further west , none of the campaigns after 1529 achieved the decisive victory that would secure the new Ottoman possessions .