Afonso de Albuquerque set sail in April 1511 from Goa to Malacca with a force of 1,200 men and seventeen or eighteen ships. Following his capture of the city on 24 August 1511, it became a strategic base for Portuguese expansion in the East Indies; consequently the Portuguese were obliged to build a fort they named "A Famosa" to defend it. That same year, the Portuguese, desiring a commercial alliance, sent an ambassador, Duarte Fernandes, to the kingdom of Ayudhya, where he was well received by king Ramathibodi II. In 1526, a large force of Portuguese ships under the command of Pedro Mascarenhas was sent to conquer Bintan, where Sultan Mahmud was based. Earlier expeditions by Diogo Dias and Afonso de Albuquerque had explored that part of the Indian Ocean, and discovered several islands new to Europeans. Mascarenhas served as Captain-Major of the Portuguese colony of Malacca from 1525 to 1526, and as viceroy of Goa, capital of the Portuguese possessions in Asia, from 1554 until his death in 1555. He was succeeded by Francisco Barreto, who served with the title of "governor-general".