Siege of Vienna ( 1485 ) The Siege of Vienna was a decisive siege of the Austro - Hungarian War in 1485 . It was a consequence of the ongoing conflict between Frederick III and Matthias Corvinus . The fall of Vienna meant its merging to Hungary from 1485 to 1490 . Matthias Corvinus also moved his royal court to the newly occupied city . The siege . In the year 1483 - 84 Vienna was being already cut from the Empire since all of his concentric defensive rings had fallen , i . e . Korneuburg , Bruck , Hainburg and later Kaiserebersdorf . One of the most important battles was Battle of Leitzersdorf , which made the next year ' s siege possible . City was perished by famine though Emperor Frederick III succeeded in providing some vital supplies with a breakthrough of sixteen vessels on the Danube to the city . On the 15th January , Matthias called the city to surrender but captain von Wulfestorff refused to do so in a hope of an Imperial relief . The blockade was fully sealed when Matthias attacked Kaiserebersdorf . There he was an unaware subject of an assassination attempt when a cannonball nearly killed him . He suspected of treachery as the aim was too precise from a long distance that only one who knew the whereabouts of the King could fire it so . He accused Jaroslav von Boskowitz und Černahora of bribery who was the brother of his mercenary captain Tobias von Boskowitz and Černahora . Without any chance to clear himself Jaroslav was decapitated . His brother Tobias was became so frustrated he returned to the service of Frederick and led his campaigns of reconquer after the death of Matthias in 1490 . After Kaiserebersdorf was captured in mid - 1485 the fate of Vienna turned inevitable . Matthias placed his armies on the Hundsmühle flour mills and in Gumpeudorf on the south of the Wien RiverThe King previously imported seventeen siege guns to Austria , and ordered the constant shooting of the city and the construction of two siege towers one of which had been burnt by the resisting militia of Vienna . Matthias intruded into Leopoldstadt in May 15 that made the final assault feasible . The Viennese people realized this and negotiated to deliver the inner city to the Hungarian King . Their only condition was the reassurance of their citizen privileges and a free passage . On 1 June in head of a military parade Matthias entered the downtown fort . Aftermath . In the Salzburg manifest Frederick ordered the Austrian States to refuse Matthias ' demand for the assembly of an Imperial Congress . He also put forward that soon to be Emperor Maximilian I would come to an aid . According to tradition this is the origin of A . E . I . O . U . a said to be secret message to all Austrian provinces . At the end of the Matthias ' campaign Hungary controlled all of Upper Austria as well and remained under his control to his death in 1490 . Administrative issues . Matthias deprived Vienna of its staple right , a right that violated the commercial interests of the nearby countries so much , they formed the Visegrád Group to secure a bypass route detouring the city . The city in counterpart enjoyed a tax free status under Matthias rule . He also delegated a member , Stefan Zápolya to the Council of Vienna but left the rest of city fathers intact . He rewarded him the city of Ebenfurth and appointed him as the captain of Vienna and governor of the Austrian provinces incorporated into Hungary . The bishop of Pécs Sigismund Ernust was promoted the vice - governor while Nikolaus Kropatsch took care of the military affairs . The prominent captains received houses in Vienna .