Château de Blois
King Henry decided to strike first. On December 23, 1588, at the Château de Blois, Henry of Guise and his brother, the Cardinal de Guise, were lured into a trap and were murdered. The Duke of Guise had been highly popular in France, and the league declared open war against King Henry. The Parliament of Paris instituted criminal charges against the King, who now joined forces with his cousin, Henry of Navarre, to war against the League.