The death of Hus enshrined him at once as a martyr and a national hero in the memory of his followers among the Czechs. They raised a storm of denunciation against Sigismund and expressed their resentment by widespread attacks on orthodox priests and churches. The Catholics retaliated in kind, and Bohemia was in a state of civil war when the death of Wenceslas (August 16, 1419) brought Sigismund to the tottering throne. The new king’s talent for conciliation and compromise was useless in the heated religious atmosphere. Pope Martin V urged him on against the Hussites and promised him imperial coronation as his reward. At his prompting, Sigismund raised a motley host in Germany and launched it into Bohemia under the banner of a papal Crusade (March 1, 1420). But the invaders were thrown back from the walls of Prague, and on July 7, 1421, Sigismund was declared deposed by the Bohemian assembly of estates. The shock of defeat forced Sigismund to attempt a fuller mobilization of German resources. Under the traditional system, princes and cities had been allowed to fix at their own discretion the quota of men provided by each when a royal campaign was in prospect. Naturally, both estates used their discretionary power to reduce contributions to a minimum. In 1422, however, Sigismund himself fixed the strength of the contingents demanded from the individual princes and cities throughout Germany. The response was disappointing. In 1426 the king raised his requirements, but to no effect. Hence the yearly campaigns against the Hussites were waged largely by mercenary armies. To meet the rising costs, the Diet of Frankfurt was persuaded in 1427 to vote a general tax, the so-called Common Penny. But there was little enthusiasm in Germany for the Crusade; massive evasions of payment occurred, and the strength of local feeling hampered the coercion of defaulters.

In 1429–30 the irrepressible Hussites swept through Saxony, Thuringia, and Franconia in a destructive foray. Sigismund, exploiting the general alarm, reverted to the older system and demanded contingents from each prince and city. The response improved, and a large army invaded Bohemia, only to meet complete disaster in 1431 at Taus (now Domažlice, in the Czech Republic). It was evident that the veteran Hussites could not be crushed by force. Sigismund therefore welcomed the opportunity to transfer the problem of reconciling the Hussites with the church to the Council of Basel (1431–49). The Hussite extremists, the Taborites, were inflexible. They condemned the hierarchical system of church government and affirmed the priesthood of all true believers. Hence the council conducted its long and arduous negotiations with the majority party among the Hussites—the Calixtines, or Utraquists, who were prepared to accept the grant of communion in both kinds as a basis of settlement. The Utraquist nobles annihilated the protesting Taborites at the Battle of Lipany (May 30, 1434) and made peace with the council by the Compact of Iglau (July 5, 1436), which conceded them communion in both kinds and reunited them with the Roman Catholic church. The Utraquist nobles extracted far better terms from Sigismund as the price of their recognition. He agreed to accept the guidance of Czech councillors in governmental affairs, to admit only Czechs to public office, to grant an amnesty for all offenses committed since the death of Wenceslas, and to allow the Czechs a large measure of autonomy in their civil and religious life. It is unlikely that the slippery Sigismund intended to honour these pledges, but they cleared the way for his triumphant return to Prague in August 1436.

In Germany the Hussite threat had clearly revealed the inadequacies of the existing financial and military systems, but the incentive to press Sigismund’s reforms to a successful conclusion faded when the Hussite peril was scotched by negotiation. The general apathy was demonstrated in 1434, when Sigismund proposed to the princes a land peace embracing the whole of Germany. The abolition of private wars and feuds by such a peace was undeniably a paramount necessity. The princes themselves, however, were among the chief offenders against law and order, and their nominal approval of the plan deceived no one. Sigismund himself, increasingly absorbed in crucial negotiations with the Hussites, did not persevere, and the project gathered dust in the imperial archives. The impulse he gave to the cause of reform did not, however, fade entirely, though Sigismund did not live to see the sequel. His death on December 9, 1437, terminated the tenure of the German throne by the house of Luxembourg and opened the door of opportunity to the Habsburg dynasty.