Why did Dutch fleets blockade Goa in 1603 and 1639?

The Dutch blockades of Goa in 1603 and 1639 were part of a broader strategic effort to establish control over the eastern seas and secure a monopoly on the spice trade.1

To achieve this, the Dutch sought to eliminate their European rivals, beginning with the Portuguese, who had previously held a monopoly on trade in the Indian Ocean. By blockading Goa—the capital of the Portuguese empire in Asia—the Dutch aimed to weaken Portuguese influence and disrupt their maritime dominance. Although these blockades significantly contributed to the decline of Portuguese power in the region, they were ultimately unsuccessful in capturing the city.123