From 1412 to 1423, Sigismund campaigned against the Republic of Venice in Italy. The king took advantage of the difficulties of Antipope John XXIII to obtain a promise that a council should be called in Constance in 1414 to settle the Western Schism. He took a leading part in the deliberations of this assembly, and during the sittings travelled to France, England, and Burgundy in a vain attempt to secure the abdication of the three rival popes. The council ended in 1418, having resolved the Schism and — of great consequence to Sigismund's future career — having the Czech religious reformer, Jan Hus, burned at the stake for heresy in July 1415. The complicity of Sigismund in the death of Hus is a matter of controversy. He had granted Hus a safe conduct and protested against his imprisonment; and Hus was burned during Sigismund's absence.