The Battle of Leitzersdorf was a battle between the Holy Roman Empire and the Kingdom of Hungary in 1484. Fuelled by the earlier conflicts of Matthias Corvinus and Frederick III, Holy Roman Emperor it marked the end of anti-Ottoman preparations and initiations of a holy war. It was the only open field battle of the Austro-Hungarian War, and the defeat meant – in long terms – the loss of the Archduchy of Austria for the Holy Roman Empire. Background Since the successful siege of Hainburg in October 1482 Queen Beatrice of Naples worked on the restoration of peace. In 1482 she envoyed the Provost of Bratislava, Georg Schönberg, Johann Hessler, Dean of Friesach and Gerhard Peuscheren, locum tenens of Fresach, repeatedly to start mediation with Johann Beckensloer Archbishop of Vienna and counselor of the Emperor. The Queen's intention with this was that Beckensloer could pose as a peace broker rather than a pro-imperial official. She offered the chance to earn himself fame by trading back the lost Salzburg area via this supposed treaty. Even though the return of these forts were demanded previously by the Emperor himself it was never realized and Matthias held them to his death. The following year, the war resumed because despite the negotiations, the parties never came to an agreement. In January 1483 the Kőszeg was captured and in April Klosterneuburg fell as well, and by constant plundering the Hungarians tried to weaken the enemy's strength. Matthias in order to concentrate the full force against the Emperor so in January 1483 he has sent agents even to the Porte to begin negotiations on a ceasefire, which had a positive outcome. He immediately reported it to the Holy Roman electoral principalities. Matthias declared he was not willing to defend the Christianity anymore unless other countries joined him. Premise The Hungarians attacked Lower Austria from three directions. István Dávidházy marched to Bruck an der Leitha and besieged it. On 24 February the city surrendered and on 12 March the castle was captured as well. The second wave with captain Tobias von Boskowitz and Černahora reached Krems and Stein and waited in a nearby river island. The third army led by Péter Geréb invaded the Duchy of Styria and the Duchy of Carinthia to block the Holy Roman forces from uniting. Meanwhile, Matthias occupied Kahlenberg in April and Dávidházy went on to encircle Korneuburg. The Emperor decided to