The Spanish and Tausug versions of the landmark Sulu–Spanish Treaty of 1836 reflect different intentions

24 Mar 2026

In the second half of the 1830s, several indigenous overlords in the Sulu–Mindanao–Borneo region began signing treaties, marking a new phase of power negotiations. These agreements created a system aimed at controlling trade and protecting mutual interests during a time of major social and economic change in the Philippines and maritime Southeast Asia. This system of treaties, which has not been documented in published literature before, included agreements with the Sultanate of Sulu (September 23, 1836), the island of Basilan (December 6, 1836), the Sultan of Maguindanao (May 22, 1837), the chiefs (datus) of Sarangani (May–June 1838), and the Mandaya chiefs in Davao (1838). These were signed with Spanish representatives, such as the Governor General in Manila, the Governor of Zamboanga, or Spanish naval officers.

This essay focuses on the Sulu-Mindanao-Borneo region in the 1830s and zooms in on the Capitulaciones (Spanish) and the Kapiturasyun (Tausug) versions of a treaty concluded between the Spanish Crown and the Sultanate of Sulu in 1836/37. It compares the different versions of the treaty texts from the perspective of a system of treaties across the region. Uneven historiographical attention has led to myth-building and a controversy over whether the treaty would have established Spanish sovereignty over the Sulu sultanate. To add nuance to this claim, the study examines the specificities of the treaties together with a large set of complementary sources. A deep, comparative reading sheds light on the motivations and strategies that accompanied the entire process of planning, negotiating, and ratifying the treaty and the consequences it had for directly and indirectly participating parties.

This article contributes to both Southeast Asian history and the growing field of new diplomatic history. It examines the landmark Sulu–Spanish Treaty of 1836 to explore the motivations of the Spanish and, in particular, the Tausug sultan and chiefs. By analyzing both the original Spanish and Tausug versions of the treaty, the study highlights their differences and the intentions behind them. In doing so, it deepens our understanding of Sulu’s history, its international entanglements, and the unique process of treaty-making between Sulu and Spain in the context of Southeast Asia and the Spanish colonies.

Authors: Birgit Tremml-Werner (Department of History, Stockholm University), Eleonora Poggio (Department of Cultural Sciences, Linnaeus University) and Ariel Lopez (Asian Center, University of the Philippines Diliman)

Read the full paper: https://brill.com/view/journals/dipl/6/2/article-p284_005.xml?ebody=Abstract%2FExcerpt

The Spanish and Tausug versions of the landmark Sulu–Spanish Treaty of 1836 reflect different intentions

In the second half of the 1830s, several indigenous overlords in the Sulu–Mindanao–Borneo region began signing treaties, marking a new phase of power negotiations. These agreements created a system aimed at controlling trade and protecting mutual interests during a time of major social and economic change in the Philippines and maritime Southeast Asia. This system of treaties, which has not been documented in published literature before, included agreements with the Sultanate of Sulu (September 23, 1836), the island of Basilan (December 6, 1836), the Sultan of Maguindanao (May 22, 1837), the chiefs (datus) of Sarangani (May–June 1838), and the Mandaya chiefs in Davao (1838). These were signed with Spanish representatives, such as the Governor General in Manila, the Governor of Zamboanga, or Spanish naval officers.

This essay focuses on the Sulu-Mindanao-Borneo region in the 1830s and zooms in on the Capitulaciones (Spanish) and the Kapiturasyun (Tausug) versions of a treaty concluded between the Spanish Crown and the Sultanate of Sulu in 1836/37. It compares the different versions of the treaty texts from the perspective of a system of treaties across the region. Uneven historiographical attention has led to myth-building and a controversy over whether the treaty would have established Spanish sovereignty over the Sulu sultanate. To add nuance to this claim, the study examines the specificities of the treaties together with a large set of complementary sources. A deep, comparative reading sheds light on the motivations and strategies that accompanied the entire process of planning, negotiating, and ratifying the treaty and the consequences it had for directly and indirectly participating parties.

This article contributes to both Southeast Asian history and the growing field of new diplomatic history. It examines the landmark Sulu–Spanish Treaty of 1836 to explore the motivations of the Spanish and, in particular, the Tausug sultan and chiefs. By analyzing both the original Spanish and Tausug versions of the treaty, the study highlights their differences and the intentions behind them. In doing so, it deepens our understanding of Sulu’s history, its international entanglements, and the unique process of treaty-making between Sulu and Spain in the context of Southeast Asia and the Spanish colonies.

Authors: Birgit Tremml-Werner (Department of History, Stockholm University), Eleonora Poggio (Department of Cultural Sciences, Linnaeus University) and Ariel Lopez (Asian Center, University of the Philippines Diliman)

Read the full paper: https://brill.com/view/journals/dipl/6/2/article-p284_005.xml?ebody=Abstract%2FExcerpt