While Portuguese and Spanish activity in the region had weakened, the English had built fortified trading posts on tiny Ai and Run islands, ten to twenty kilometres from the main Banda Islands.
With the British paying higher prices, they were significantly undermining Dutch aims for a monopoly.
As Dutch-British tensions increased in 1611 the Dutch built the larger and more strategic Fort Belgica above Fort Nassau.

In 1615, the Dutch invaded Ai with 900 men whereupon the British retreated to Run where they regrouped.
That same night, the British launched a surprise counter-attack on Ai, retaking the island and killing 200 Dutchmen.
A year later, a much stronger Dutch force attacked Ai.
This time the defenders were able to hold off the attack with cannon fire, but after a month of siege they ran out of ammunition.
The Dutch slaughtered the defenders, and afterwards strengthened the fort, renaming it 'Fort Revenge'.
While Portuguese and Spanish activity in the region had weakened, the English had built fortified trading posts on tiny Ai and Run islands, ten to twenty kilometres from the main Banda Islands. With the British paying higher prices, they were significantly undermining Dutch aims for a monopoly. As Dutch-British tensions increased in 1611 the Dutch built the larger and more strategic Fort Belgica above Fort Nassau.
In 1615, the Dutch invaded Ai with 900 men whereupon the British retreated to Run where they regrouped. That same night, the British launched a surprise counter-attack on Ai, retaking the island and killing 200 Dutchmen. A year later, a much stronger Dutch force attacked Ai. This time the defenders were able to hold off the attack with cannon fire, but after a month of siege they ran out of ammunition. The Dutch slaughtered the defenders, and afterwards strengthened the fort, renaming it 'Fort Revenge'.
Governorate of the Banda Islands