Also this is the list of ruling authorities, could you add it to the menu?
Matyáš Korvín, as Anti-King 1474-1490
Barbara von Teschen-Auschwitz, 1490-1493
Johann von Schellenberg, 1493-1506
Georg von Schellenberg, 1506-1523
Georg der Fromme von Brandenburg-Ansbach-Kulmbach, 1523-1543
Georg Friedrich von Brandenburg-Ansbach, 1543-1603
Joachim Friedrich von Brandenburg, 1603-1606
Johann Georg von Brandenburg-Ansbach, 1606-1621
source:
https://de.wikipedia.org/wiki/Herzogtum_J%C3%A4gerndorf
According to Borys Paszkiewicz "Silesian Mints and Coinage..." the first Heller was minted in Krnov in 1475, so no need to go earlier:
https://www.jstor.org/stable/42667173?read-now=1&refreqid=excelsior%3Abc59888d20a099bb94f238f98ee850fc&seq=27#page_scan_tab_contents