quality:correction
First anti-Hussite crusade

After the death of his childless brother Wenceslaus, Sigismund inherited a claim on the Bohemian crown, though it was then, and remained until much later, in question whether Bohemia was a hereditary or an elective monarchy, especially since the line through which Sigismund claimed the throne had accepted that the Kingdom of Bohemia was an elective monarchy elected by the nobles, and thus, the regent of the kingdom (Čeněk of Wartenberg) also explicitly stated that Sigismund had not been elected as a reason for Sigismund's claim to not be accepted. A firm adherent of the Church of Rome, Sigismund was aided by Pope Martin V, who issued a bull on 17 March 1420 proclaiming a crusade "for the destruction of the Wycliffites, Hussites and all other heretics in Bohemia". Sigismund and many German princes arrived before Prague on 30 June at the head of a vast army of crusaders from all parts of Europe, largely consisting of adventurers attracted by the hope of pillage. They immediately began a siege of the city, which had, however, soon to be abandoned. Negotiations took place for a settlement of the religious differences.

The united Hussites formulated their demands in a statement known as the " Four Articles of Prague ". This document, the most important of the Hussite period, ran, in the wording of the contemporary chronicler, Laurence of Brezova, as follows:

1. The word of God shall be preached and made known in the kingdom of Bohemia freely and in an orderly manner by the priests of the Lord.

2. The sacrament of the most Holy Eucharist shall be freely administered in the two kinds, that is bread and wine, to all the faithful in Christ who are not precluded by mortal sin – according to the word and disposition of Our Saviour.

3. The secular power over riches and worldly goods which the clergy possesses in contradiction to Christ's precept, to the prejudice of its office and to the detriment of the secular arm, shall be taken and withdrawn from it, and the clergy itself shall be brought back to the evangelical rule and an apostolic life such as that which Christ and his apostles led.

4. All mortal sins, and in particular all public and other disorders, which are contrary to God's law shall in every rank of life be duly and judiciously prohibited and destroyed by those whose office it is.

These articles, which contain the essence of the Hussite doctrine, were rejected by King Sigismund, mainly through the influence of the papal legates, who considered them prejudicial to the authority of the pope. Hostilities therefore continued. However, Sigismund was defeated at the Battle of Vítkov Hill on July 1420.

Though Sigismund had retired from Prague, his troops held the castles of Vyšehrad and Hradčany. The citizens of Prague laid siege to Vyšehrad (see Battle of Vyšehrad), and towards the end of October 1420 the garrison was on the point of capitulating through famine. Sigismund tried to relieve the fortress but was decisively defeated by the Hussites on 1 November near the village of Pankrác. The castles of Vyšehrad and Hradčany now capitulated, and shortly afterwards, almost all Bohemia fell into the hands of the Hussites.