After father's death the Hungarian rule quickly collapsed in the Habsburg lands (Styria, Carniola, Lower Austria).
The Bohemians (Vladislaus Jagiellon) and Poles (John I Albert and the Holy Roman Emperor Maximilian I also claimed the Hungarian throne.
Due to the foreign wars of Matthias in Austria and Bohemia and his extraordinary taxes, the lords (just like Kinizsi) did not support his son.
A some days later John's supporters, Sigismund Ernuszt bishop of Pécs, Lawrence of Ilok and Bertalan Beriszló recruited an army and entered Buda.
During that time, John hesitated and wanted to return to the capital, but his supporters blackmailed him and forced him to fight the battle with Kinizsi and Báthory.