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Anglo-Siamese Treaty of 1909

The Anglo-Siamese Treaty of 1909 or Bangkok Treaty of 1909 was a treaty between the United Kingdom of Great Britain and Ireland and the Kingdom of Siam signed on 10 March 1909, in Bangkok.[2] Ratifications were exchanged in London on 9 July 1909.[3]

Anglo-Siamese Treaty of 1909 [1]
Bangkok Treaty
  • Transfer of Kelantan, Tringganu, Kedah and Perlis to the United Kingdom of Great Britain and Ireland.
  • Britain recognized Siamese sovereignty over Patani
Signed 10 March 1909
Location Bangkok
Effective 9 July 1909
Language English



The Kingdom of Siam operated under the command of a monarchy. Siam’s ability to maintain its independence from British and French colonizers has often been accredited to the ruling family, the Chakkri dynasty. Although there were many previous monarchs within the Chakkri dynasty, the prominent figure in maintaining independence in Siam begins with Rama I, who ruled from 1782-1809. Unlike previous rulers, Rama I followed a technocratic ruling style which often involved the consultation of social elites on political matters and Sangha (Buddhist Monks) on religious matters. His consultations with the Siamese elites became a political necessity within his successors.[4] Rama I was succeeded by Rama II, who ruled from 1809-1824. Rama II greatest accomplishment was the establishment of a government of ministers. It is towards the end of his reign, in 1820, that the British enter into the scene seeking control of Penang. Rama II was followed by Rama III, whose reign lasted from 1824-1851. During his reign, he began the process of allowing British concessions in exchange for support, and later the same would be done with the French.[5] In 1826, in an effort to establish independence, Rama III and British officials signed the Burney Treaty. The Burney Treaty stated that Kedah, Kelantan, Perlis and Terengganu were Thai provinces while Penang and Province Wellesley belonged to the British while Thailand would not interfere with British trade in Kelantan and Terengganu.[6] After Rama III’s reign came to an end, a succession crisis brought Mongkut to power, who reigned from 1851-1868. Under Mongkut’s leadership the Bowring Treaty of 1855 was signed. The Treaty provided British citizens living in Siam with extraterritoriality which meant that British individuals would have their own country’s laws applied to them rather than Siam’s. Mongkut constantly made concessions to the British and French to maintain independence in Siam until, in 1868, he was succeeded by Chulalongkorn, who ruled from 1868 to 1910. Chulalongkorn was a moderniser, similar to his predecessors, in such that he abolished slavery, centralised revenues, created a national educational system, and maintained Siam’s independence to concessions such as the Anglo-Siamese Treaty of 1909.


The Anglo-Siamese Treaty of 1909, signed under the leadership of Chulalongkorn, is split into 8 articles;

Article 1Edit

"The Siamese government transfers to the British government all rights of suzerainty, protection, administration and control whatsoever which they possess over the states of Kelantan,Tringganu, Kedah, Perlis, and adjacent islands. The frontiers of these territories are defined by the boundary protocol annexed hereto.”

Article 2Edit

The transfer provided for in the preceding article shall take place within thirty days after the ratification of this treaty.

Article 3Edit

A mixed commission, composed of Siamese and British officials and officers, shall be appointed within six months after the date of ratification of this treaty and shall be charged with the delimitation of the new frontier. The work of the commission shall be commenced as soon as the season permits, and shall be carried out in accordance with the boundary protocol annexed hereto. Subjects of his majesty the king of Siam residing within the territory described in article1 who desire to preserve their Siamese nationality will, during the period of six months after the ratification of the present treaty, be allowed to do so if they become domiciled in the Siamese dominions. His Britannic majesty’s government under take that they shall be at liberty to retain their immovable property within the territory described in article1. It is understood that in accordance with the usual custom where a change of suzerainty takes place, any concessions within the territories described in article 1 hereof to individuals or companies, granted by or with the approval of the Siamese government, and recognised by them as still in force on the date of the signature of the treaty, will be recognised by the government of his Britannic majesty

Article 4Edit

His Britannic majesty’s government undertake that the government of the Federated Malay States shall assume the indebtedness to the Siamese government of the territories described in article1.

Article 5Edit

The jurisdiction of the Siamese International Courts, established by article8 of the treaty of 3 September 1883, shall,under the conditions defined in the jurisdiction protocol annexed hereto, be extended to all British subjects in Siam registered at the British consulates before the date of the present treaty. This system shall come to an end, and the jurisdiction of the International Courts shall be transferred to the ordinary Siamese courts after the promulgation and the coming into force of the Siamese codes, namely, the penal code, the civil and commercial codes, the codes of procedure, and the law for organisation of courts. All other British subjects in Siam shall be subject to the jurisdiction of the ordinary Siamese courts under the conditions defined in the jurisdiction protocol.

Article 6Edit

British subjects shall enjoy throughout the whole extent of Siam the rights and privileges enjoyed by the natives of the country, notably the right of property the right of residence and travel. They and their property shall be subject to all taxes and services, but these shall not be other or higher than the taxes and services which are or maybe imposed by law on Siamese subjects. It is particularly understood that the limitation in the agreement of 20 September 1900, by which the taxation of land shall not exceed that on similar land in Lower Burmah, is hereby removed. British subjects in Siam shall be exempt from all military service, either in the army or navy, and from all forced loans or military exactions or contributions.

Article 7Edit

The provisions of all treaties, agreements, and conventions between Great Britain and Siam, not modified by the present treaty remain in full force.

Article 8Edit

The present treaty shall be ratified within four months from its date. In witness where of the respective plenipotentiaries have signed the present treaty and affixed their seals. Done at Bangkok, in duplicate, the 10th day of March, in the year 1909.”[7]


This agreement has had a long-lasting effect on both Thailand and the Federation of Malaysia. The border between them was mainly drawn by this treaty. The incremental tide of discontent generated by the Anglo-Siamese Treaty of 1909 may have, in part laid the foundations for the South Thailand insurgency in Pattani, Yala and Narathiwat from the 1960s to the present. The agreement effectively divided the northern Malay states into two parts. The area around modern Pattani (Malay: ڤتنا (Patani)), Narathiwat (Malay: منارة (Menara)), southernmost Songkhla (Malay: سيڠڬورا (Singgora)), Satun (Malay: مقيم ستل (Mukim Setul)) and Yala (Malay: جال (Jala)) remained under Thai control, while Thailand relinquished its claims to sovereignty over Kedah (Thai: ไทรบุรี (Saiburi)), Kelantan (Thai: กลันตัน (Kalantan)), Perlis (Thai: ปะลิส (Palit)) and Terengganu (Thai: ตรังกานู (Trangkanu)) which integrated the British sphere of influence as protectorates. These four states, along with Johor, later became known as the Unfederated Malay States. Although the treaty had cultural impacts and was responsible for giving away pieces of land, it was also responsible for maintaining the independence of Siam.

King Rama V gave a comment concerning the treaty as: "We have no special interest in these dominions...If these territories to be ceded to Britain, we will lose only the golden and silver flowers. There is not any physical loss unless those tributes..."[8]


  1. ^ Siam. Treaty with Great Britain Hamilton King. May 13, 1909.
  2. ^ U.S. Department of State, Bureau of Intelligence and Research, Office of the Geographer, "International Boundary Study: Malaysia - Thailand Boundary," No. 57 Archived 16 September 2006 at the Wayback Machine., 15 November 1965.
  3. ^ Great Britain, Treaty Series, No. 19 (1909)
  4. ^ al.], ed. by Norman G. Owen ; David Chandler ... [et (2005). The emergence of modern Southeast Asia : a new history. Honolulu, Hawaii: University of Hawaii Press. p. 94. ISBN 978-0-8248-2890-5.
  5. ^ al.], ed. by Norman G. Owen ; David Chandler ... et (2005). The emergence of modern Southeast Asia : a new history. Honolulu, Hawaii: University of Hawaii Press. p. 95. ISBN 978-0-8248-2890-5.
  6. ^ Suwannathat-Pian, Kobuka (1986). "The 1839-41 Settlements of Kedah: The Siamese Compromise". Journal of the Malaysian Branch of the Royal Asiatic Society. 59 (1): 33–48. JSTOR 41493034.
  7. ^ "Treaty between Great Britain and Siam". The American Journal of International Law. 3 (4): 297–304. 1909. doi:10.2307/2212641. JSTOR 2212641.
  8. ^ Original word in Thai : "เราไม่มีผลประโยชน์เป็นพิเศษแต่อย่างใดในบรรดาหัวเมืองเหล่านี้…หากเราต้องสูญเสียหัวเมืองเหล่านี้ให้แก่อังกฤษ เราจะขาดแต่เพียงดอกไม้เงินดอกไม้ทอง นอกเหนือไปจากเครื่องราชบรรณาการนี้แล้ว ก็ไม่มีการสูญเสียทางด้านวัตถุอื่นใดอีก..."