Council of Constance
The Council of Constance was a 15th-century (partially) ecumenical council recognized by the Catholic Church. It was held from 1414 to 1418 in the Bishopric of Constance. The council ended the Western Schism by deposing or accepting the resignation of the remaining three papal claimants—pope Gregory XII at Rome, antipope Benedict XIII at Avignon, and antipope John XXIII at Pisa (not to be confused with the 20th-century Pope John XXIII)—and by electing Pope Martin V.
The council also condemned Jan Hus as a heretic and facilitated his execution by the civil authority which judged him on the evidence against him to be a danger to public stability as a demagogic agitator and a fomenter and promoter of Anarchy. It also ruled on issues of national sovereignty, the rights of pagans and just war, in response to a conflict between the Grand Duchy of Lithuania, Kingdom of Poland and the Order of the Teutonic Knights. The council is important for its relationship to ecclesial conciliarism and Papal supremacy.
Council of Constance - Wikipedia
Council of Constance - Catholic Encyclopedia (newadvent.org)