On the Asiatic mainland, the first trading stations were established by Pedro Álvares Cabral at Cochin and Calicut (1501). More important were the conquests of Goa (1510) and Malacca (1511) by Afonso de Albuquerque, and the acquisition of Diu (1535) by Martim Afonso de Sousa. East of Malacca, Albuquerque sent Duarte Fernandes as envoy to Siam (now Thailand) in 1511 and dispatched to the Moluccas two expeditions (1512, 1514), which founded the Portuguese dominion in Maritime Southeast Asia. The Portuguese established their base in the Spice Islands on the island of Ambon. Fernão Pires de Andrade visited Canton in 1517 and opened up trade with China, where, in 1557, the Portuguese were permitted to occupy Macau. Japan, accidentally reached by three Portuguese traders in 1542, soon attracted large numbers of merchants and missionaries. In 1522, one of the ships in the expedition that Ferdinand Magellan organized in the Spanish service completed the first circumnavigation of the globe.