Prince Damrong in Preah Vihear, 1930

On 30 January 1930, Prince Damrong Rajanupab of Thailand arrived at Preah Vihear (also called Śikhareśvara, ​“Summit of God Shiva”) for a private visit (not as the head of an official expedition from the Siamese court of King Prajadhipok (Rama VII), as it has been claimed) with several Thai noblemen and one of his daughters, Princess Phun Phitsamai Diskul. The French commissioner for the Cambodian province of Kompong Thom, and chief-archaeologist Henri Parmentier for Angkor, welcomed the Thai visitors and guided them on the Dangrek hills for them to see its famed centuries-old Hindu temple.

The pictures taken by the unnamed photographer have recently resurfaced on Internet, fueling the ongoing territorial controversy that had been settled by the the International Court of Justice in 1962, and again in 1965. These same pictures had then played a major role in the Court deliberations, the Cambodian side arguing that the visit was a de facto recognition of the sovereignty of the Protectorate (and thus Cambodia) on Preah Vihear.

A few remarks seem necessary here:

• Somdet Krom Phraya Damrong Rachanuphap, a younger brother of King Chulalongkorn and former Minister of Interior, himself an archaelogist and Southeast Asian art collector, had always entertained excellent relations with the French researchers, to begin with George Coedès, who spent ten years researching the Bangkok Royal Library archives. In the EFEO Chronicle for the year 1924, for instance, we read that ​“Mlle Suzanne Karpeles, on a mission in Cambodia since August, went to Angkor in November in order to welcome — with M. Marchal — HRH Prince Damrong Rajanubhab, who had traveled from Bangkok to visit the monuments”. The Prince acknowledged the expertise of EFEO researchers on Preah Vihear, having exchanged knowledge with French explorers since as long as 1910, when Lunet de Lajonquiere identified some inscriptions part of the Prince’s collection.
• During a talk at the Foreign Correspondents’ Club of Thailand, Thai historian Charnvit Kasetsiri showed these photos of Prince Damrong and the French officials posing together beneath the French flag, and noted that the Prince ​“accepted that Preah Vihear belonged to French Indochina,” in contrast with the official history taught to Thai children, ​“history infected with nationalism.”
• During the debates at the International Court, one expert reporting for the Thai side, Volker Grabowsky of the Asia-Africa-Institute at University of Hamburg, maintained that ​“the Preah Vihear temple has been merely of local importance for the Kui or Suai people inhabiting the Dongrak Mountains on both sides of the present-day Thai-Cambodian border. It seems that the temple was abandoned completely in later times and only visited by forest monks for meditation practices. In the year 1899 the Siamese High Commissioner (kha luang thesaphiban) of Monthon Isan visited the inaccessible area south of Kantharalak and discovered by mere chance the temple ruins, overgrown by climbing plants.”
• Several years later, Prince Damrong published the impressions of his visit along with several of these photos in his book ​“Report on a survey of archaeological sites in monthon Nakhòn Ratchasima (จดหมายเหตุการเสด็จตรวจโบราณวัตถุสถานมณฑลนครราชสีมา). Although he undertook his visit to Preah Vihear as a private person, Prince Damrong, who at that time held the position as Chief of the Supreme State Council (อภิรัฐมนตรี), was welcome by his French hosts as a high-ranking state-guest. According to his daughter, the Prince did not dare protest the display of French authority, ​“given the arrogant and intrusive behaviour of the French and given the painful experiences of the past.” Princess Phun Phitsamai Diskul also noted that ​“it was generally known at the time that we only give the French an excuse to seize more territory by protesting. Things had been like that since they came into the river Chao Phya with their gunboats and their seizure of Chanthaburi.”
• In July 2020, near the anniversary of Preah Vihear inscription to UNESCO Heritage List, the Lek Prapai Viryaphant Foundation ติดตามบทความ วิดีโอ และรายการต่างๆ เพิ่มเติมได้ที่ posted a collection of these photographs, claiming their unique ownership: 
• The Foundation is under the name of flamboyant Thai tycoon Lek Viriyaphan เล็ก วิริยะพันธุ์ (1914, Bangkok ‑17 Nov 2000, Bangkok) who, in addition to be a successful businessman, was a fervent researcher in Thai arts and culture (along with his wife, Prapai), and conceived such as cultural attractions as Muong Boran (Ancient Siam) open-air museum park in Samut Prakhan, the Erawan Museum and the Sanctuary of Truth.
• Prince Damrong was a frequent guest of EFEO in Cambodia since 1924. In Bulletin de l’EFEO XXIV (Hanoi, 1925, p 647), we read: ​“Le prince Damrong Rajanuhhab de Siam, accompagné de trois princesses ses filles et de M. Georges Coedès, a fait récemment une visite au Cambodge, au cours de laquelle il a passé dix jours à Ankor [sic], du 22 novembre au 1^er décembre 1924. Reçu par M. Marchal et Mlle Karpelès au nom de l’Ecole française, le prince a visité minutieusementles monuments et étudié avec sa haute compétence d’historien et d’archéologue toutes les questions que posent aux savants ces incomparables ruines. La méthode suivie dans le dégagement et la consolidation des édifices a particulièrement retenu son attention, au moment où le Service archéologique du Siam, récemment fondé sur son initiative et placé sous sa direction, commence sa carrière et se trouve en face d’une tâche analogue. S. A. R. a bien voulu témoigner à plusieurs reprises sa flatteuse appréciation des résultats obtenus.” [Prince Damrong Rajanuhhab of Siam, accompanied by three princesses, his daughters, and Mr. Georges Coedès, recently made a visit to Cambodia, during which he spent ten days in Ankor [sic], from November 22 to December 1, 1924. Welcomed by Mr. Marchal and Miss Karpelès on behalf of the French School, the prince carefully visited the monuments and studied with his high skill as a historian and archaeologist all the questions brought to scholars by these incomparable ruins. The method followed in the clearance and consolidation of the buildings particularly called its attention, at a time when the Archaeological Service of Siam, recently founded on his initiative and placed under his direction, begins its career and finds it facing of a similar task. S. A. R. was kind enough to testify on several occasions his flattering appreciation of the attained results.”] See Prince Damrong’s own account of his 1924 visit.
• In their paper ​“Heritage and Nationalism in the Preah Vihear Dispute Voices from Cambodia. Discourses on the Preah Vihear Conflict”, [Research Report] EFEO, Ecole française d’Extrême-Orient/ Université de Hambourg, 2016, Volker Grabowsky and Sok Udom Deth noted that the International Court of Justice ruled in favor of Cambodoia in 1959, basing ​“its arguments above all on the validity of the French map from the fall of 1908 (scale 1:200,000) and also on the absence of protest on the part of the Thai authorities against this map. In the view of the majority of the judges, the fact that Prince Damrong did not complain against the hoisting of the French national flag during his visit of Preah Vihear in early 1930 was interpreted as a tacit consent. Because of Damrong’s highranking position in the Siamese state apparatus, the private character of his visit – emphasized by the Thai side – was refuted. Damrong’s archaeological fact-finding mission was seen as an at-least half-official visit. Therefore, according to the legal principal Qui tacit consentire videtur si loqui debuisset ac potuisset (“He who keeps silent is held to consent if he must and can speak”), also called ​“estoppel” in international law, the ICJ ruled that Thailand had to accept he frontier as fixed in the Annex I map.