Twenty Years' War

Twenty Years' War
Date 1769 – 1788 (19 years) Location Borneo Philippines Result Bruneian victory Pirates continue to raid Brunei until the arrival of James Brooke Territorial changes All Bruneian lands reclaimed; Status quo ante bellum
Belligerents
Bruneian Empire Rajahnate of Mengkabong	Sulu Sultanate Pirates	Kingdom of Spain (1769) Captaincy General of the Philippines (1769)
Commanders and leaders
Omar Ali Saifuddien I # Muhammad Tajuddin Awang Aliwaddin Pengiran Temenggong Ampa Sharif Ali Raja Tua of Mengkabong[note 1]	Ferdinand I #[note 2] Muhammad Israil  Azim ud-Din II Datu Teting	Charles III # José Antonio Raón y Gutiérrez
Units involved
Bruneian Army	Sulu Army	Spanish Army Spanish garrison in Manila
Strength
around ~1,000–4,000 warriors.[1][2][3] 2,000 Sama-Bajau[3]	Unknown	Unknown
Casualties and losses
Unknown	Unknown	Unknown

the Twenty Years' War or the Bruneian–Sulu War was a conflict between the Sulu Sultanate and the Bruneian Empire. Brunei also fought Spain briefly as well.

This war was also the first time Brunei ever used flintlock muskets, as they began acquiring them in the late 17th century and early 18th century^[2][4]

The Sultan of Sulu was instated by the British to control Manila in 1763.^[5] Sultan Omar Ali Saifuddin who learned about the situation in Manila, he was displeased as Azim ud-Din I was a apostate.^[6] As a result, he commanded an attack on the Sulu Sultanate in Manila with his forces under the command of Pehin Orang Kaya Di-Gadong Seri Lela Awang Aliwaddin.^[7]

This article is part of a series on the
History of Brunei
Imperial era Sultanate of Sulu Rajahnate of Maynila Sultanate of Sarawak
Colonial era Barisan Pemuda Borneo campaign BMO Borneo Brunei People's Party Brunei revolt North Borneo Federation Bruneian Independence Japanese occupation National Development Plan State Council White Rajahs Sarawak Labuan North Borneo
Post-independence Brunei National Solidarity Party Amedeo Crisis National Development Party Golden Jubilee of Hassanal Bolkiah
Topics Capital punishment Constitution Diplomacy Education Islam LGBT Military Navy Monarchy Slavery Sultan Transport
See also List of years in Brunei

The mission did not arrive in Manila until 1769 because the expedition's preparations took so long. Sultan Azim ud-Din I (Alimuddin) had already departed Manila for Sulu in 1764 after the Treaty of Paris, therefore Manila was under Spanish rule when the siege began.^[8] The siege was successful besieged for Brunei, capturing it in the process.^[9]

The Sulu Sultanate then despatched a force under the command of Datu Teting to attack Balambangan in 1775, the leaders of Balambangan sought safety in Labuan after the British quickly established a presence in Brunei.^[10] When the two forces clashed, Datu Teting surrendered and his troops fled back to Sulu after learning that the warriors of Brunei, led by Pengiran Temenggong Ampa, were far too strong for them to defeat.^[11][3]

In 1788, A Sulu army attacked many coastal villages around Sabah as an attempt to invade Brunei, lead by Datu Teting who previously burned Balambangan before retreating, arriving to Kampung Sembulan in said year. They were later defeated by again Pengiran Temenggong Ampa, Sharif Amir and Raja Tua of Mengkabong. Sharif Ali later became the caretaker of Kampung Sembulan one of many coastal villages in Sabah.^[3]

Thanks to their numerical and military advantage over Sulu, Brunei effectively defeated the Sulu Sultanate. Though piracy raids continued after the war, Brunei reclaimed all of their lost territory in the war against Sulu. Brunei stopped any more Sulu invasions against Brunei. The war was pivotal for restoring Brunei's dominance in Borneo and stopped anymore foreign incursions into Brunei until the mid–19th century when James Brooke arrived.

Who would later be responsible of one of many factors that caused the decline of the Bruneian Sultanate, making it decline heavily into 1870 to 1888.^[12][13] Which eventually forced Sultan Anak Hashim to sign the Protectorate Agreement in 1888.