It occurred after Emperor Matthias sent emissaries to explain why Rudolph II's Letter of Majesty was not being used to protect Heinrich von Thurn's band of Hussites. However, Matthias chose two councillors to Ferdinand II of Bohemia, Jaroslav Martinic and Vilém Slawata. Outraged at the choice of ambassadors and their message, the citizens attempted to kill the councillors. For 10 points—name this 1618 incident which sparked the Thirty Years War, 
It occurred after Emperor Matthias sent emissaries to explain why Rudolph II's Letter of Majesty was not being used to protect Heinrich von Thurn's band of Hussites. However, Matthias chose two councillors to Ferdinand II of Bohemia, Jaroslav Martinic and Vilém Slawata. Outraged at the choice of ambassadors and their message, the citizens attempted to kill the councillors. For 10 points—name this 1618 incident which sparked the Thirty Years War, in which the councillors were thrown from a window.
It occurred after Emperor Matthias sent emissaries to explain why Rudolph II's Letter of Majesty was not being used to protect Heinrich von Thurn's band of Hussites.