After the Battle of Kosovo (1448) he was left for a time, as a hostage for his father, in the hands of George Brankovic (1427–1456), despot of Serbia.

[2] At the diet of Buda (1455) he resigned all his dignities, because of the accusations of Ulrich II, Count of Celje, and other enemies of his house, but a reconciliation was ultimately patched together and he was betrothed to Anna, the daughter of the palatine, Ladislaus Garai.

After his father's death in 1456, he was declared by his enemy Ulrich II (now Captain General of Hungary with significant power) responsible for the debts allegedly owed by the elder Hunyadi to the state; but he defended himself so ably at the diet of Futak (October 1456) that Ulrich feigned a reconciliation, promising to protect the Hunyadis on condition that they first surrendered all the royal castles entrusted to them.

[4] The terrified young king thereupon pardoned Hunyadi, and at a subsequent interview with his mother at Temesvár swore that he would protect the whole family.

But on arriving there he was arrested on a charge of plotting against the king, condemned to death without the observance of any legal formalities, and beheaded on 16 March 1457.