Predeceased by his legitimate son, John II was succeeded by his cousin the duke of Beja, as Manuel I (1495–1521), known as “the Fortunate.” Manuel, who assumed the title of “Lord of the Conquest, Navigation, and Commerce of India, Ethiopia, Arabia, and Persia,” inherited, because of the work of John II, a firmly established autocratic monarchy and a rapidly expanding overseas empire. Drawn toward Spain by the common need to defend their overseas interests as defined by the Treaty of Tordesillas (1494), Manuel nourished the hope that the whole peninsula could be united under the house of Aviz; to that end he married Isabella, eldest daughter of Ferdinand and Isabella. However, she died in 1498 while giving birth to a son, Miguel da Paz. This child, recognized as heir to Portugal, Castile, and Aragon, died in infancy. Manuel then married Isabella’s sister Maria (died 1517) and eventually Eleanor, sister of the emperor Charles V.