Signed on March 23, 1907, in Bangkok, the Franco-Siamese Treaty marks a decisive step in the history of relations between colonial France and the Kingdom of Siam, present-day Thailand. This diplomatic agreement ends several decades of territorial rivalries over Cambodia and Laos, two regions central to French colonial ambitions in Southeast Asia. Under the treaty, France returns the provinces of Dan Sai and Krat to Bangkok, while Siam cedes the territories of Battambang, Siem Reap, and Sisophon, formerly under its control, to the French Indochinese Federation.
Beyond the redefinition of borders, the 1907 treaty symbolizes a geopolitical balance between the European colonial power and the only Asian kingdom to have escaped direct colonization. It also testifies to the diplomatic skill of the Siamese sovereigns, concerned with preserving the country’s independence while negotiating with imperial powers. Its effects are still visible today, particularly in the configuration of Cambodian and Thai borders.
Here is the translated text of the treaty:
TREATY
The President of the French Republic and His Majesty the King of Siam, following the delimitation operations undertaken in execution of the Convention of February 13, 1904, desirous, on the one hand, to ensure the final settlement of all questions relating to the common frontiers of Indo-China and Siam through a reciprocal and rational system of exchanges, desirous, on the other hand, to facilitate relations between the two countries by the progressive introduction of a uniform system of jurisdiction and by extending the rights of French nationals established in Siam.
Have resolved to conclude a new treaty and have for this purpose appointed as their plenipotentiaries, namely:
The President of the French Republic, Mr. Victor-Émile-Marie-Joseph Collin de Plancy, Envoy Extraordinary and Minister Plenipotentiary of the French Republic to Siam, Officer of the Legion of Honour and of Public Instruction.
His Majesty the King of Siam, H.R.H. Prince Devawongse Varoprakar, Knight of the Order of Maha Chakri, Grand Officer of the Legion of Honour, etc., Minister of Foreign Affairs.
Who, having exchanged their full powers, found to be in good and due form, have agreed upon the following provisions:
Article 1. The Siamese Government cedes to France the territories of Battambang, Siem Reap and Sisophon, the boundaries of which are defined by Clause I of the annexed delimitation protocol.
Art. 2. The French Government cedes to Siam the territories of Dansai and Kratt, the boundaries of which are defined by Clauses I and II of the said protocol, as well as all islands situated to the south of the Lemling Passage, up to and including Koh Kut.
Art. 3. The handover of these territories shall take place by both parties within a period of twenty days after the date on which the present treaty has been ratified.
Art. 4. A mixed commission, composed of French and Siamese officers and officials, shall be appointed by the two contracting parties within a period of four months after the ratification of the present treaty and shall be entrusted with delimiting the new frontiers. It shall begin its work as soon as the season permits and shall carry it out in accordance with the delimitation protocol annexed to the present treaty.
Art. 5. All Asians who are French subjects or protégés and who register at the French consulates in Siam after the signing of the present treaty, in application of Article 9 of the Convention of February 13, 1904, shall be answerable to the ordinary Siamese courts.
The jurisdiction of the Siamese international courts, the establishment of which is provided for by Article 12 of the Convention of February 13, 1904, shall, under the conditions set forth in the annexed jurisdiction protocol, be extended throughout the Kingdom of Siam to Asian French subjects and protégés, referred to in Articles 10 and 11 of the same Convention and currently registered at the French consulates in Siam.
This regime shall cease, and the jurisdiction of the international courts shall be transferred to the ordinary Siamese courts after the promulgation and enforcement of the Siamese codes (Penal Code, Civil and Commercial Codes, Codes of Procedure, Law on Judicial Organization).
Art. 6. Asian French subjects and protégés shall enjoy, throughout the entire Kingdom of Siam, the rights and prerogatives enjoyed by the country’s nationals, notably the rights of property, free residence, and free movement.
They shall be subject to ordinary taxes and contributions.
They shall be exempt from military service and shall not be liable to requisitions and extraordinary taxes.
Art. 7. The provisions of the former treaties, agreements, and conventions between France and Siam, which are not modified by the present treaty, remain in full force and effect.
Art. 8. In case of difficulty in interpreting the present treaty, which is drawn up in French and Siamese, the French text alone shall be authoritative.
Art. 9. The present treaty shall be ratified within a period of four months from the day of its signature, or sooner if possible.
In witness whereof, the respective Plenipotentiaries have signed the present treaty and affixed their seals thereto.
Done at Bangkok, in duplicate, this 23rd day of March, one thousand nine hundred and seven.
Signed: V. Collin De Plancy
Devawongse Varoprakar
