In 1162 Emperor Barbarossa began a second siege of Milan, which would end with the destruction of the city. In 1163 Alexander III excommunicated Rainald, who had loudly proclaimed in these negotiations the right of the emperor to dispose of the papal see. Basing his action on the Roncalian decrees issued at the Diet of Roncaglia, near Piacenza, in 1158, Rainald was once more successfully employed in Italy in the affairs of the emperor. When Victor IV died, Rainald, of his own volition and without waiting for the consent of the emperor, elected at Lucca a new antipope, Paschal III. Frederick would hardly have continued the schism. Rainald knew this and therefore wished to force the emperor to continue the struggle for imperial supremacy.