Spanish–Moro conflict
The Spanish initiated the conflict by conquering the Philippines and invading Moro territory in an effort to subjugate the region to their rule since the 1500s. When the Spanish conquered the Muslim Kingdom of Maynila, a vassal of the Sultanate of Brunei, the Islamic rajah, Rajah Sulayman resisted the Spanish. Manila then became the capital of the Spanish Philippines after the conquest, with the Spanish forcibly converting people to Catholicism. The Spanish–Moro Wars started with the Castille War, a war between Spaniards and the Sultanate of Brunei. (The term "Moro" at this time included Muslim Tagalogs who were ruled by the Sultanate of Brunei).
Battles of La Naval de Manila
In view of their previous failures to disrupt the Spanish Empire's trade in Asia, the Dutch decided to seize the Philippines, feeling certain that they were strong enough to carry out the attacks. From the time they conquered the Spanish settlement in the north of Formosa in 1642, the Dutch became increasingly eager to attack Manila because they knew the city lacked strong defenses and that it was unable to receive enough aid because the Spanish were occupied by the wars in Europe.