There is little information about him. He was first mentioned in the charter issued for four members of his family on 12 February 1419.[2] He was appointed Ban of Severin (Szörény) by King Albert in 1439, along with his brother.[5] Thereafter he participated in his brother's early campaigns against the Ottomans. He was probably killed in a battle in this capacity in 1440 or 1441. He was buried in Gyulafehérvár (today: Alba Iulia, Romania). His brother wrote of him as "the valiant of the valiant", showing that John the younger was regarded a brave soldier.[6]
Engel, Pál (1996). Magyarország világi archontológiája, 1301–1457, I. [Secular Archontology of Hungary, 1301–1457, Volume I] (in Hungarian). Budapest: História, MTA Történettudományi Intézete. ISBN963-8312-44-0.
Pop, Ioan-Aurel (2005). "Transylvania in the 14th century and the first half of the 15th century (1300–1456)". In Pop, Ioan-Aurel; Nägler, Thomas (eds.). The History of Transylvania, Vol. I. (Until 1541). Romanian Cultural Institute (Center for Transylvanian Studies). pp. 247–298. ISBN973-7784-00-6.
Teke, Zsuzsa (1980). Hunyadi János és kora [John Hunyadi and his Times] (in Hungarian). Gondolat. ISBN963-280-951-3.