[2] Following that (around 1500) he married Princess Margaret of Sagan (Żagań), daughter of Jan II the Mad and widow of Nicholas Bánffy de Alsólendva.
[7] While his elder brother became bishop and held various positions in the royal court, John II managed the family estates in Csáktornya (Čakovec) and Međimurje (today in Croatia).
They persuaded the late King's illegitimate son, John Corvinus to give them their father's former copper mines at Besztercebánya (now Banská Bystrica in Slovakia) in 1494.
[7] According to contemporary sources, John Ernuszt, Jr. was much less brilliant mind than his father and brother – Hans Dernschwam, commercial trustee of the Fuggers in Hungary characterized him as a "simple-minded pious man" (German: ein freÿer einfältiger Mann).
[11] In 1503, he was excommunicated by the Holy See due to physical abuse of the local schoolmaster in Verőce (Virovitica, Croatia), however the Diocese of Pécs acquitted him.
[12] Sigismund's legal heir was his younger brother, John according to his last will to avoid full confiscation for the royal treasury.
[7] In 1514, John initiated a second lawsuit against the three retainers before Archbishop Thomas Bakócz, who also acted as a papal legate during that time.
John's lawyers accused the suspects of murder, the falsification of Sigismund's last will and embezzlement of 1,3 million gold florins.
[13] The Hungarian royal court, for political reasons and intricate relationship between the baronial groups, prevented the lawsuit continued abroad.
Following John's death, his only living son Caspar has initiated a new trial in 1536, however he died in 1540 and the House of Ernuszt became extinct, making the lawsuit is obsolete.