The Council of Constance (1414-1418) represented the decisive effort to resolve the Western Schism, a crisis that previous councils and political maneuvers had failed to overcome. Convened under the authority of Emperor Sigismund, the assembly adopted a strategic approach that went beyond simple mediation. Its primary challenge was not merely to choose one claimant over the others but to establish a legal and theological framework that legitimized the deposition of multiple sitting popes.
This framework was enshrined in the pivotal decree Haec Sancta (1415). The document formally articulated the doctrine of conciliarism, asserting that a general council derived its authority directly from Christ and that all Christians, including the pope himself, were bound to obey its decisions. This declaration provided the council with the ideological justification necessary to act with supreme authority. It was a radical reordering of ecclesiastical power, positioning the collective body of the Church above its monarchical head.
Armed with this authority, the council systematically dismantled the rival papal courts. It secured the abdication of the Roman Pope Gregory XII and formally deposed both the Avignon Pope Benedict XIII and the Pisan Pope John XXIII. With the papal office declared vacant, the assembled cardinals and national delegates proceeded with a new election. The elevation of Pope Martin V in 1417 effectively healed the schism that had fractured European Christendom for nearly forty years, restoring a single, universally recognized pontiff to the See of Peter.
