Great War in Mindanao and Sulu (1521-1900) (21st Century Crisis)

The Great War in Mindanao and Sulu (Filipino: Malaking Digmaan sa Mindanao at Sulu, Malay: Pertempuran Besar di Mindanao dan Sulu, Spanish: Gran Guerra en Mindanao y Sulu) also known as the Great War in the South (Filipino: Malaking Digmaan sa Timog, Malay: Pertempuran Besar di Selatan, Spanish: Gran Guerra del Sur) was a 300-year long conflict between the native kingdoms in the Philippine islands of Mindanao and the Sulu Archipelago against the Spanish Empire and their Filipino cohorts and native collaborators.

It began as war between the Spanish Empire and a six-kingdom alliance in Mindanao, namely the Sultanates of Maguindanao, Sulu, Lanao and Buluan and the Rajahnates of Butuan and Bukidnon. The latter two previously accepted Spanish colonization and Roman Catholicism, and were integrated as vassal states to the Spanish Empire. However, their rulers rebelled and joined their southern Moro Muslim counterparts in fighting the Spanish Empire.

The Spanish Empire eventually ended up vanquishing two of the six kingdoms, decisively defeating the Rajahnates of Butuan (1526) and Bukidnon (1525). It slowly and barely defeated the Sultanates of Maguindanao (1675) and Buluan (1680), with Buluan accepting its status as an autonomous protectorate of the Spanish Empire - effectively dissolving the alliance. However, it could not conquer the Sultanate of Sulu or the Sultanate of Lanao, who used reinforced strength, constant guerillia-style warfare and exploited the weakness of the Spanish forces due to them having to exhaust their military means fighting the forces of Maguindanao and Buluan. In addition, ex-Maguindanaon soldiers were employed by the armies of Sulu and Lanao to avenge their loss.

The Sultanate of Sulu eventually grew too powerful, and invaded the Zamboanga Peninsula to drive the Spanish forces away, after successfully taking over their forts and establishing their own stronghold.

The fighting persisted all throughout, until the Americans helped the Moros vanquish the remaining Spanish forces away from Mindanao and Sulu Archipelago.

As to who emerged victorious is a point of conflict. To the Moro and Filipino nationalists, it was a victory for the Alliance since the Spanish could not subdue all of the kingdoms and subsequently failed to do so, miserably. To Spanish historians and Hispanophilic Filipinos, it was a Spanish and Filipino victory since by defeating four of the six kingdoms, they had successfully vanquished and dissolved the alliance.