During the Age of Discovery (~1480-1600) the Europeans - principally the Portuguese - sought to dominate the spice trade of the East Indies which for them encompassed the Indian Ocean, the Persian Gulf, the Gulf of Aden, the Strait of Malacca, the Malabar Coast and much of what is now known as Malaysia and Indonesia.

As with European encroachment into Asia and Africa in general, there were often 'forceful takings' of cities and ports, such as Calicut (1502), Malacca (1509), Goa (1510), and Muscat (1508) and with this came acquiring certain goods and spices by force too.

The brutatlity and ruthlessness of the Portuguese in establishing their presence and initial wealth in Asia is not to be underestimated, and there was much pillaging and privateering during these first decades of Portuguese presence in the Indian Ocean.

However, despite the strongarm tactics of the Portuguese (and later Dutch, French and British), the majority of the money long-term was made was through 'legitimate' trade. This 'legitimate' trade was such that often the terms favoured the Portuguese greatly, however it was conducted - albeit often with coercion - through two consenting parties.

Initially, the goods and gifts that de Gama brought with him to India on his first voyage in 1498 were considered paltry and meaningless (depsite their profitability on the distant West African Coast). These included cloth, hats, sugar, oil and honey, and none of which were deemed of particular interest according to Castaneda.

Nevertheless, by 1520 there existed a bountiful Portuguese trade within the East Indies which didn't just profit the Portuguese. Indeed, there were many nations and groups that were made exceedingly wealthy and powerful through trade with the Portuguese, such as the Vijayanagara Empire of Southern India. However the Portuguese were ruthless in acquiring a greater monopoly of the spice routes of the Indian Ocean, and thus a monopoly over the spice trade in Europe.

Principally, as K S Matthew has shown, the Portuguese traded goods brought from Europe such as wine, metals, guns and linens with the various merchants of Asia. But the principal factor in Portuguese trading success was their ability to place themselves at the centre of existing trade routes and dominate the transactions that took place between longstanding nations and peoples. For example, Portuguese merchants would buy spices from Malabar, sell them to Chinese or Malay merchants at a steep profit, and then purchase more spices from Malabar to ship back to Europe and sell in the Mediterranean and Lisbon. Portugal also had the power of controlling crucial trading ports and shipping lanes in India, and could collect duties and taxes on transactions that took place in their cities and docks.

These were the principal revenue generators for Portugal in the first half of the 1500s. As the rise of the Dutch East India Company and interloping Europeans came about from the 1600s, and the Portuguese union with Spain from 1580 decapitated Portuguese mercantile independence, the Portuguese presence in the East Indies became overshadowed. Nevertheless, it had established a greater European presence in the East Indies than ever before and laid the foundations for Northern European Joint-Stock Companies to place themselves in the centre of commercial power, backed up of course by immense naval might and the construction of forts to secure their position.

Hope that helps!

Sources: Herman Lopes de Castaneda, The First Book of the Historie of the Discoveries and Conquests of the East India by the Portingals, London (1582)

K S Matthew; Portugese Trade with India and the Theory of Royal Monopoly in the C16th, in Proceedings of the Indian History College, Vol. 40 (1979)

William Brookes Greenleigh; The voyage of Pedro Álvares Cabral to Brazil and India: from contemporary documents and narratives, New Delhi (1995)