John Corvinus was the illegitimate son of Matthias Corvinus, King of Hungary, and his mistress, Barbara Edelpöck.

Vladislaus II, also known as Vladislav, Władysław or Wladislas, was King of Bohemia from 1471 to 1516 and King of Hungary and of Croatia from 1490 to 1516. As the eldest son of Casimir IV Jagiellon, he was expected to inherit Poland and Lithuania. George of Poděbrady, the Hussite ruler of Bohemia, offered to make Vladislaus his heir in 1468. George needed Casimir's support against the rebellious Catholic noblemen and their ally King of Hungary Matthias Corvinus. The Diet of Bohemia elected Vladislaus king after George's death, but he could rule only Bohemia proper because Matthias, whom the Catholic nobles had elected king, occupied Moravia, Silesia and both Lusatias. Vladislaus tried to reconquer the four provinces with his father's assistance but was repelled by Matthias.