Owing to his marriage with a Bavarian princess and to his military command in the imperial service, his brother was allied more closely with the old church and resisted the new reforming efforts.
Som følge af sit ægteskab med en bayersk prinsesse og sin militære position i den kejserlige tjeneste holdt Kasimir i højere grad fast i den gamle kirke og strittede imod forandringsanstrengelserne.