Den upalení mistra Jana Husa. Johannes Hus (Czech: Jan Hus) (ca. 1369/1370 - 6 July 1415) was a Bohemian professor who is regarded as a forerunner of the Reformation. This is a national celebration in Czechia on July 6th.

In his time, three popes disputed each other's authority. There were great tensions between the Czech population and the German clergy; Jan Hus was the interpreter of this.

Hus used the reflections of John Wyclif (c. 1330-1384) on the church as a community of the elect. He adhered to official church doctrine, but criticized the church organization and later also the papacy. Hus called the church back to the Bible. He was repeatedly condemned and finally sentenced to the stake by the Council of Constance (1414), despite a safe conduct from Roman king Sigismund. He was burned at the stake on the Grote Markt, near the Tyn Church in Prague. Now there is a large monument, with his reclining image, on the place where the scaffold used to be.

The supporters of Hus, the Hussites, took up arms when Sigismund of Luxembourg also became king of Bohemia in 1419. There were two groups of the Hussites: the Utraquists and the Taborites. The Utraquists wanted the sacrament administration under both guises (sub utraque specie); the Taborites were much more radical and rejected as unbiblical than Hus had done.

"Sancta simplicitas" (Sacred Simplicity)

When Hus stood at the stake, he must have said this, shaking his head, to an old woman who came forward with a twig for the stake. But it is also possible that Hieronymus van Praag said this when he met the same fate a year later.