The first Prague Defenestration was a reaction to the arrest of several radical Hussites by Prague City Hall because they were preaching about Communion in Both Kinds. During the early morning hours on July 30th 1419, a radical Hussite priest named Jan Želivský was preaching in the Virgin Mary Sněžná church. He managed to radicalize his audience so much that the armed and furious mob moved toward the New Town City Hall, where they demanded, through the speech
of Jan Želivský, the release of their brethren, and when this was refused by the council members (supposedly a rock was thrown at Želivský), the mob overpowered the guards and raided the City Hall without hesitation. The assault was apparently commanded by Jan Žižka, a later Hussite leader. The council members were thrown out of the windows and then killed by the enraged mob in the street.
This event is seen as what triggered the Hussite Wars long period.
