Meanwhile , the convocation sejm of 1648 had elected a new king , Jan Kazimierz II Vasa . Wiśniowiecki supported other candidates , such as George I Rákóczi and Karol Ferdynand Vasa ( Jan Kazimierz 's brother ) . Due to the opposition from Jeremi 's detractors , he was not granted a hetman position , although after a full two days of debate on the subject he was granted a document that stated he had a " power equal to that of a hetman . " Wiśniowiecki faction , arguing for increase in army size , was once again marginalized by the faction that hoped for a peaceful resolution . In the end , the King and most of the szlachta were lulled into a false sense of security , and the military was not reinforced significantly . To add an insult to an injury , the coronation sejm of January – February 1649 , held in Kraków , revoked Wiśniowieck 's regimentarz rank .