Holy Roman Emperor and King of Hungary, Croatia, and Bohemia
"The authority of the universal council stands higher than any promise of an emperor."— Justifying the revocation of safe conduct for Jan Hus at Constance
Sigismund of Luxembourg (1368–1437) was the last emperor of the House of Luxembourg, reigning as Holy Roman Emperor, King of Hungary and Croatia, and King of Bohemia. A highly intelligent and multilingual statesman, he successfully resolved the four-decade Western Schism, yet his failure to protect Jan Hus provoked the devastating Hussite Wars.
Born in Nuremberg in 1368 to Emperor Charles IV, Sigismund was crowned King of Hungary and Croatia in 1387 through marriage. To stem the rapid advance of the Ottoman Empire into the Balkans, he organized a grand Western coalition in 1396. However, his chivalric crusader army suffered a crushing defeat against Sultan Bayezid I at the Battle of Nicopolis, with Sigismund narrowly escaping by boat down the Danube.
Elected King of the Romans in 1410, Sigismund convened the Council of Constance in 1414 to heal the Great Schism that had divided Western Christendom among three rival popes. While the council successfully unified the papacy, it condemned reformer Jan Hus as a heretic. Despite having issued Hus an imperial safe conduct, Sigismund bowed to conciliar pressure and allowed Hus to be burned at the stake, an act viewed in Bohemia as an unforgivable betrayal that inflamed nationalist and religious rebellion.
Following the sudden death of his brother Wenceslaus IV in 1419 amid the First Defenestration of Prague, Sigismund claimed the Bohemian throne. The Bohemian estates violently rejected his claim, branding him a traitor. In response, Sigismund and Pope Martin V proclaimed five successive Anti-Hussite Crusades, drawing knights from Germany, Austria, and across Europe. Each expedition met catastrophic disaster before the wagon fortresses and coordinated artillery tactics of Jan Žižka and Prokop the Great.
Realizing that military conquest was impossible, Sigismund pursued diplomacy at the Council of Basel, forging secret negotiations with the moderate Hussites (Utraquists). After the Utraquists defeated the radical Taborites at the Battle of Lipany in 1434, Sigismund accepted the Compacts of Basel, formally recognizing Communion under both kinds for the laity. He was finally received in Prague as King of Bohemia in 1436. Having no male heirs, his death in 1437 marked the extinction of the House of Luxembourg.