Persecution of Muslims
The Philippines is predominantly a Christian society with a complicated history of relations between Islam and Christianity. Despite historic evidence of Islamization spreading throughout the islands in the 13th–16th centuries, the archipelago came under Spanish rule in the 16th century. The Spanish proselytized many natives, and labelled those who remained Muslims as "Moro", a derogatory term recalling the Moors, an Islamic people of North Africa who occupied parts of Spain for several centuries. Today, this term "Moro" is used to refer to the indigenous Muslim tribes and ethnic groups of the country. When the Spanish came to the Philippine islands, most of the natives in Luzon and Visayas were pagans with Muslim minorities, and while Spanish proselytized many natives, many Muslims in Luzon and Visayas were not exempted by the Spaniards from the Spanish Inquisition, wherein Muslims to become Catholics or die for their faith. Those who remained Muslims are only the natives of Mindanao and Sulu which the Spaniards did not invade or had control of only briefly and partially.
Sulu
The navigational error that landed Ferdinand Magellan in Limasawa brought awareness of Europe to the Philippines and opened the door to Spanish colonial incursion. The Spaniards introduced Catholicism and a political system of church-state dichotomy, which encountered fierce resistance in the devastating Moro wars from 1578 to 1899. The Sultanate of Sulu formally recognised Spanish sovereignty in Tawi-Tawi and Sulu in middle of 19th century, but these areas remained partially ruled by the Spanish as their sovereignty was limited to military stations and garrisons and pockets of civilian settlements, until they had to abandon the region as a consequence of their defeat in the Spanish–American War.