He was to fight the Huguenot forces for some years; he fought at the Battle of Arques in 1589. That same year, Charles Emmanuel was the governor of Paris, as the Huguenot forces, led by Henry of Navarre besieged Paris. During the siege, King Henry III of France perished, and Henry of Navarre soon declared himself King Henry IV of France. Charles Emmanuel escaped, and fought the newly proclaimed King at the Ivry in 1590, which was a decisive loss for the Catholic League. The same year he commanded Catholic forces during the Siege of Paris, successfully defending the city.