By the beginning of 1581 events in Western Europe had escalated to such an extent that the activities of the duke of Anjou began to take on added significance. In January 1580 the aged Cardinal Henry of Portugal died after having named Philip II as his successor. Philip was unable to take possession of his new crown, however, except by conquest. Led by the veteran duke of Alva, the Spanish army invaded Portugal and captured Lisbon in late August. The significance of Philip's annexation of Portugal was twofold. With the addition of the Portuguese coastal salt deposits, the Azores, and above all the Portuguese overseas empire, Philip strengthened his already formidable position as the most powerful prince in Western Europe. To the other European nations, especially the smaller Protestant states, the Spanish goal of a res publica Christiana became all the more real. On the other hand, because Philip was required to keep his army in Portugal throughout 1581 in order to hold on to his newly acquired crown, the military strength of the Spanish army in the Netherlands was severely weakened. The Spanish and Italian units of Philip's army had been withdrawn completely, and the few troops that remained did not receive regular pay. With the growing threat of Spanish hegemony of Europe, the withdrawal of the ‘army of Flanders’ to Portugal thus presented Queen Elizabeth and Henry III with a golden opportunity to interfere in the Netherlands on the side of the rebels.