Meanwhile, after the peace of Crespy (September 1544), Emperor Charles V (1519–56) began to put down Protestantism by force. Pending the Diet of Worms in 1545, the Emperor concluded a covenant of joint action with the papal legate Cardinal Alessandro Farnese, with Paul III agreeing to aid in the projected war against the German Protestant princes and estates. This prompt acquiescence was probably grounded on personal motives: since the Emperor was preoccupied in Germany, the moment now seemed opportune for the Pope to acquire for his son Pier Luigi the duchies of Parma and Piacenza. Although these belonged to the Papal States, Paul III planned to overcome the reluctance of the cardinals by exchanging these papal duchies for the less valuable domains of Camerino and Nepi. The Emperor agreed, welcoming the prospect of 12,000 infantry, 500 cavalry, and considerable funds from the Pope.