Before his death on 6 April 1490, King Matthias asked his captains and barons to pledge an oath to his son John Corvinus and secure his succession to the throne. Though John was the biggest estate holder in Hungary and had the command over the Black Army, his stepmother, Queen Beatrice of Naples, invited two heirs, the Holy Roman Emperor Maximilian I and Polish prince John I Albert, for an assembly to be held at Buda to discuss who would inherit the throne. The first based his claim on the Peace Treaty of Wiener Neustadt, while the latter on his family ties. Furthermore, the Hungarian barons invited a third pretender, the King of Bohemia and brother of John Albert, Vladislaus II. After the barons double-crossed John Corvinus, he escaped from the capital and was moving to Pécs, when he was attacked midway at Szabaton village and suffered a defeat from which he could retreat. No parts of the Black Army were – yet – involved, as their core was stuck in Silesia and Styria. Their famed captains Blaise Magyar and Paul Kinizsi joined the pretenders' side, John Albert and Vladislaus, respectively; the latter subsequently became the legitime king.