The Ming Tombs in Beijing, China.

Source: Zhenya. (n.d.) The Interior Environment of Dingling. Adobe Stock.

Historical Context and the Question of Sovereignty

A key issue with the 1405 Agreement is that Sulu was not yet a unified sultanate at the time. Most scholarly sources place the official establishment of the Sulu Sultanate in 1457 under Sultan Sharif ul-Hashim. Some historians, such as Najeeb Saleeby, suggest the sultanate may have emerged as early as sometime between 1407 and 1436, while Cesar Adib Majul argues for 1450 as the more likely date. However, no credible academic research supports the claim that Sulu was a formalized political entity in 1405. Assertions to the contrary largely stem from modern revisionist e-narratives attempting to bolster the credibility of the agreement for modern profit.

The notion of early sovereignty is further weakened by the fact that the first recorded use of the title "Sultan" in Sulu, appearing as "Asulutan" (an informal linguistic variation of "Sultan"), is found in a Spanish document from 1579. This suggests that the formalization of both the state and the ruling position developed much later than proponents of the 1405 claim assert. Similarly, from an Eastern perspective, Chinese records from the early 15th century describe Sulu as a fragmented territory divided into three separate kingdoms. Further documentation from 1417 confirms the presence of multiple rulers, indicating that Sulu had not yet developed into a centralized state.

Without a defined territorial authority or a singular ruling leader, any diplomatic engagement in 1405 would have lacked the necessary criteria for a legitimate treaty between sovereign states. At most, such an agreement would have functioned as a tributary arrangement, a common structure in China’s diplomatic framework that integrated smaller regional entities into the Ming tributary system rather than recognizing them as independent states.

The 1405 Agreement and Its Failure

Even if the 1405 Agreement held some diplomatic weight, it was ultimately unenforceable due to unfulfilled obligations.

One of the key stipulations required Sulu to provide a detailed territorial map outlining its boundaries. However, Sulu rulers never provided this map, leading to a breakdown in the agreement’s execution. Without clear territorial demarcation, Sulu could not be properly integrated into China’s tributary network or be considered a recognized vassal state.

Furthermore, the absence of any significant Chinese intervention for Sulu following the agreement suggests that China did not treat this arrangement as a high-priority or legitimate alliance. Unlike the formal relationships established between the Ming Dynasty and other regional powers, Sulu’s engagement with China in the early 15th century remained limited to sporadic diplomatic exchanges rather than a sustained political or military relationship.

Misinterpretations of Later Sino-Sulu Relations

Another common misconception used to reinforce the legitimacy of the 1405 Agreement is the claim that Sulu’s diplomatic relationship with China continued unbroken into later centuries. While Sulu did maintain relations with China, these engagements were separate from any original agreement.

For instance, the Daily Tribune asserts that Sultan Alimud Din of Sulu met “Emperor Cheung” in the 17th century to place Sulu under Chinese protection. However, that timeline does not match up with historical records. According to several Chinese sources, including Da Ming Shi Lu and Da Qing Li Chao Shi Lu, Sultan Alimud Din (Muhammad Azim ud-Din I) corresponded with Emperor Qianlong of Qing China in the 18th century (between 1782-1784), not in the 17th century.

These interactions were centuries removed from the 1405 Agreement and were shaped by completely different geopolitical realities, including a shared concern over European colonial threats rather than any lingering obligations from the early Ming period. In fact, the correspondence, which again was never met with a formal alliance, proves that China and Sulu never had a valid or recognized treaty in 1405.

Conclusion & Significance

The 1405 Agreement between China and Sulu lacks legal credibility for two main reasons:

1. Sulu was not a sovereign state in 1405 – At the time, Sulu was politically fragmented with multiple rulers, making it ineligible for formal treaty-making.

2. The agreement’s terms were never fulfilled – The failure to provide a territorial map or sustain political engagement effectively annulled the agreement.

Furthermore, later Sulu-Sino relations were independent of this agreement and cannot be used retroactively to legitimize it. Given these facts, the 1405 Agreement does not hold any weight as a binding treaty and remains a historically weak claim, particularly for modern political or territorial assertions.

This historical misinterpretation takes on greater significance today, as Sulu claimants actively invoke the 1405 Agreement to justify their efforts to gain China’s support in ongoing disputes. Although the agreement was never formally recognized, it continues to be leveraged for political purposes despite its clear absence of historical and legal legitimacy. Accurately understanding the past is essential to preventing the manipulation of history and ensuring that historical discourse remains grounded in verifiable facts.

REFERENCES

Echeminada, P. (2025, January 21). 1405 China-Sulu Treaty Revisited. Daily Tribune. https://tribune.net.ph/2025/01/21/1405-china-sulu-treaty-revisited

Majul, C. A. (1981). An Analysis of the “Genealogy of Sulu.” Archipel, 22(1), 167–182. https://doi.org/10.3406/arch.1981.1677

Raposas, A. (2017, June 9). Paduka Batara and Pre-Colonial Philippine Foreign Relations. Filipino Historian. https://history-ph.blogspot.com/2017/06/paduka-batara.html?fbclid=IwY2xjawIIgqtleHRuA2FlbQIxMAABHUkNQ16AVYZbaqclPRmCWotbhw8YqPpfVkq-hMHTeuOR-9dUTX-NeodXdg_aem_GcC2zNC9KSz9NaokZuzvoA

Saleeby, N. M. (1908). The History of Sulu. https://www.gutenberg.org/files/41771/41771-h/41771-h.htm

The Enduring Legacy of the East King of Sulu in Chinese-Filipino Diplomacy. (2024, January 7). Asian Century Journal. https://asiancenturyph.com/2024/01/07/the-enduring-legacy-of-the-east-king-of-sulu-in-chinese-filipino-diplomacy/