died on 11 August 1456, less than three weeks after his greatest victory over the Ottomans in Belgrade. John's elder sonMatthias's brotherLadislaus became the head of the House of Hunyadi. John's conflict with Ulrich II, Count of Celje ended with Ulrich's capture and assassination on 9 November. Under duress, the King promised he would never take his revenge against the Hunyadis for Ulrich's killing. However, the murder turned most baronsincluding PalatineLadislaus Garai, Judge royalLadislaus Pálóci, and Nicholas Újlaki, Voivode of Transylvaniaagainst Ladislaus Hunyadi. Taking advantage of their resentment, the King had the Hunyadi brothers imprisoned in Buda on 14 March 1457. The royal council condemned them to death for high treason and Ladislaus Hunyadi was beheaded on 16 March. Matthias Corvinus was held in captivity in a small house in Buda. His mother Erzsébet Szilágyi and her brother Michael Szilágyi founded Szilágyi – Hunyadi League, and staged a rebellion against the King and occupied large territories in the regions to the east of the river Tisza. King Ladislaus fled to Vienna in mid-1457, and from Vienna to Praguein September, taking Matthias with him. The civil war between the Szilágyi – Hunyadi League and the barons loyal to the monarch continued until the sudden death of the young King Ladislaus on 23 November 1457. Hereafter the Hussite Regent of BohemiaGeorge of Poděbradyheld Matthias captive. Ladislaus V died childless in 1457. His elder sister Anna and her husband, William III, Landgrave of Thuringia laid claim to his inheritance but received no support from the Estates. The Diet of Hungary was convoked to Pest to elect a new king in January 1458. Pope Calixtus III's legateCardinalJuan Carvajal, who had been John Hunyadi's admirer, began openly campaigning for Matthias. The election of Matthias Corvinus as king was the only way of avoiding a protracted civil war. Ladislaus Garai was the first baron to yield. At a meeting with Michael Szilágyi and Erzsébet Szilágyi, he promised that he and his allies would promote Matthias's election, and Michael Szilágyi promised that his nephew would never seek vengeance for Ladislaus Hunyadi's execution. They also agreed that Matthias would marry the Palatine's daughter Annahis executed brother's bride. Michael Szilágyi arrived at the Diet with 15.000 troops, intimidating the barons who assembled in Buda. Stirred up by Szilágyi, the noblemen gathered on the frozen River Danube and unanimously proclaimed the 14-year-old Matthias King on 24 January. At the same time, the Diet elected Michael Szilágyi as Regent of the Kingdom of Hungary.
