Zbigniew Oleśnicki, bishop of Cracow and first Polish cardinal, was prominent figure in Poland's politics during late Władysław II's reign and reign of his young son Władysław III. Oleśnicki was ambitious and capable man, but his actions caused lots of problems for rulers of Poland, starting with controversy over rights of Jogaila's sons to the Polish throne-Oleśnicki denied them hereditary laws to the throne of Poland-they were born from non-dynastic marriage, when their older half-sister with Piast blood was still alive. Despite this there was still significant support for hereditary monarchy in Poland, although camp supporting elective monarchy, with powerful Oleśnicki on their side, prevailed. So if Oleśnicki is regalist instead and support Jogaila in his struggle to confirm rights of his sons to the Crown, Jogaila may be successful. In such situation Jogaila would not support Vytautas' coronation plans (IOTL King decided, that it is good idea to strenghten his negotiation position with Polish Royal Council, if Jogaila has bishop Oleśnicki on his side and managed to officially make his son heir of the Kingdom, there would be no need for this. Thus all that mess with Vytautas' coronation would be butterflyied away). That is first change. That is first change. Other changes in Oleśncki's behaviour would be:
-his approach towards religion (including his attitude towards Hussites) is more pragmatic than IOTL. His ITTL actions are motivated more by Poland's interest.
-Oleśnicki is against Władysław III's Hungarian adventure, seeing it as something, that would distract Poland's attention from Baltic. Thus Władysław III would not accept Hungarian offert and would not became King of Hungary. His main counter-candidate in Hungary was Lazar Branković. So would we see civil war between Lazar and Elizabeth of Luxembourg instead of OTL war between Elizabeth and Władysław? @Fehérvári Without need to fight war in Hungary Władysław would not ruin Poland's treasure and Royal domain would not be reduced like IOTL, when King needed cash in hurry, thus he has given lots of his lands to nobles as lien and never get these lands back).
-Oleśnicki convince Władysław to respect conditions of Union of Horodło and to recognize his younger brother Kazimierz as Grand Duke of Litghuania (while Władysław would keep title of Supreme Duke of Lithuania).
-When rebellion against Teutonic Order starts in Prussian towns Oleśnicki fully supports Poland's entry to the war against TO. And without royal treasure being emptied King would have money to hire mercenaries, thus Teutonic Order would be finished quickly and disaster of Chojnice would be avoided.
@krieger
-his approach towards religion (including his attitude towards Hussites) is more pragmatic than IOTL. His ITTL actions are motivated more by Poland's interest.
-Oleśnicki is against Władysław III's Hungarian adventure, seeing it as something, that would distract Poland's attention from Baltic. Thus Władysław III would not accept Hungarian offert and would not became King of Hungary. His main counter-candidate in Hungary was Lazar Branković. So would we see civil war between Lazar and Elizabeth of Luxembourg instead of OTL war between Elizabeth and Władysław? @Fehérvári Without need to fight war in Hungary Władysław would not ruin Poland's treasure and Royal domain would not be reduced like IOTL, when King needed cash in hurry, thus he has given lots of his lands to nobles as lien and never get these lands back).
-Oleśnicki convince Władysław to respect conditions of Union of Horodło and to recognize his younger brother Kazimierz as Grand Duke of Litghuania (while Władysław would keep title of Supreme Duke of Lithuania).
-When rebellion against Teutonic Order starts in Prussian towns Oleśnicki fully supports Poland's entry to the war against TO. And without royal treasure being emptied King would have money to hire mercenaries, thus Teutonic Order would be finished quickly and disaster of Chojnice would be avoided.
@krieger