At the death in 1584 of Francis, Duke of Anjou, the king's brother (which left Henry of Navarre, the Protestant champion, as heir-male), Guise concluded the Treaty of Joinville with Philip II of Spain. This compact declared that the Cardinal de Bourbon should succeed Henry III, in preference to Henry of Navarre. Henry III now sided with the Catholic League (1585), which made war with great success on the Protestants. Guise sent his cousin, Charles, Duke of Aumale, to lead a rising in Picardy (which could also support the retreat of the Spanish Armada). Alarmed, Henry III ordered Guise to remain in Champagne; he defied the king and on 9 May 1588 Guise entered Paris, bringing to a head his ambiguous challenge to royal authority in the Day of the Barricades and forcing King Henry to flee.