Daga 1412 zuwa 1423, Sigismund ya yi yaƙi da Jamhuriyar Venice a Italiya.Sarkin ya yi amfani da wahalhalu na Antipope John XXIII don samun alƙawarin cewa ya kamata a kira majalisa a Constance a 1414 don daidaita schism na Yamma.Ya taka rawa a tattaunawar da aka yi a wannan taro, kuma a lokacin zaman ya yi tattaki zuwa Faransa, Ingila da Burgundy a wani yunkuri na banza na ganin an tsige Fafaroman uku masu hamayya da juna.Majalisar ta ƙare a shekara ta 1418, bayan ta warware Schism da - babban sakamako ga Sigismund na gaba aiki - yana da mai gyara addinin Czech, Jan Hus, ya ƙone a kan gungumen azaba a watan Yuli 1415. Ƙaddamar da Sigismund a cikin mutuwar Hus shine al'amarin da ke jawo cece-kuce.Ya baiwa Hus lafiya kuma ya nuna rashin amincewa da daurin da aka yi masa;kuma an kona Hus a lokacin rashin Sigismund.