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).
Captaincy General of the Philippines
Miguel López de Legazpi, arrived in Umatac in 1565 and claimed the island of Guam for Spain, before proceeding to the Philippines, where in a short period of time they successfully incorporated to Spain's Empire Cebu, Samar, Mazaua, Leyte, and Bohol, before conquering Manila.