Ulrich II of Celje, the most powerful member of the Cilli family of Lower Styria, is named by King Ladislaus V of Hungary to Hunyadi’s office of Captain General of Hungary after the death of his rival.

Ulrich, now possessed of significant power, declares Hunyadi’s son László responsible for the debts alleged to be owing by the elder Hunyadi to the state; but László defends himself so ably at the diet of Futak (October 1456) that Ulrich feigns a reconciliation, promising to protect the Hunyadis on condition that they first surrender all the royal castles entrusted to them.

A beginning is to be made with the fortress of Nándorfehérvár (now Belgrade, Serbia) of which László is commandant.

While admitting Ladislaus V and Ulrich, László excludes their army of mercenaries.

On the following morning (November 9, 1456) Ulrich dies at the hands Celje of Hunyadi's men in unclear circumstances.

With him dies the male line of the Counts of Celje.

The terrified young king thereupon pardons Hunyadi, and at a subsequent interview with his mother at Temesvár swears that he will protect the whole family.