I've been working my way through Edmund Alexander de Schweinitz's The History of the Church Known as the Unitas Fratrum; or, The Unity of the Brethren, Founded by the Followers of John Hus (1885), and I was once again particularly struck by the episode leading up to the Thirty Years War and the Counter or Anti-Reformation that was the result.
After the 1618 Defenestration of Prague, the Protestant uprising against the Habsburg Ferdinand II, the various Protestant leaders of Bohemia (Utraquists and Lutherans) decided to reject Ferdinand's claims and instead appealed to the Elector Frederick V of the Palatinate to come and be their king.