The Jewel Robbery that Baffled the Best

It looked the perfect crime. When a box containing a string of 252 specially-made pearls and other valuable pieces of jewellery, ordered by Queen Saovabha Phongsri (the mother of the future King Vajiravudh, Rama VI), from a reputable agent in Britain and insured for £10,000, arrived in Bangkok in the middle of 1909, it was found to be empty. For almost three years the whereabouts of the pearls remained a mystery while police and diamond merchants followed a trail leading from Bangkok to Singapore, Penang, Australia, Batavia (now Jakarta), Colombo, Paris, and London.

When King Chulalongkorn made his second visit to Europe in 1907, among those accompanying him was Queen Saovabha Phongsri. In April 1909, Queen Saovabha arranged for a rope of pearls and other pieces of expensive jewellery to be been made up by the Association of Diamond Merchants, Jewellers, and Silversmiths Limited of Trafalgar Square in London.


Queen Saovabha Phongsri, later known as Queen Sri Bajarindra, with her sons.

After completing their commission, the jewellers carefully packed the items in a strong wooden box secured with four big red seals. According to some accounts, this box was placed aboard a German steamer bound for Bangkok and deposited in its strongroom. In other accounts the box was placed in the strongroom of a steamer bound for Hong Kong. When it arrived at that British colony the box was then taken to Bangkok. Either way, when the Court Chamberlain in Bangkok opened the box it was found to be empty, even though none of the four seals did not appear to have been broken. It was as if the jewels had simply vanished.


Although the pearls were insured, the insurance company refused to pay out until strenuous efforts had been made to recover the jewellery. Representatives of the Association of Diamond Merchants would spend literally thousands of pounds following up leads in the search for the pearls over the next year and a half before finally reaching a definite suspect. Their only hope at recovering the pearls and tracking the thief, or thieves, lay with the chance someone would eventually try and sell some of the distinctive pearls.

For almost 18 months the trail was cold and the jewellers association investigators completely baffled by the seemingly perfect crime. There were early suggestions that close inspection by experts revealed the seals on the strongbox were very cleverly executed copies of the originals. This meant the theft may well have occurred before the pearls even left Britain, but this idea was soon discarded when a second and more plausible explanation came to light.

The thief, or thieves, worked out it was not necessary to disturb the seals in order to get at the jewels. The lid of the strongbox was made in two pieces, tongued and grooved. One piece was 22.5 centimetres (nine inches) wide; the other was 15 centimetres (six inches) wide. By taking out the screws securing the 15cm piece, it was possible to slip it out of the larger piece. After cutting through the zinc lining on the box it was then a simple matter to remove the pearls and other items. After replacing the 22.5cm lid and refastening the screws there was no evidence of tampering. This knowledge simply expanded the number of possible scenarios for the theft: from inside Britain, on the steamer, or at its final destination in Bangkok and anywhere in-between.

The first clue came late in 1910 when it was learned that 33 pearls suspected as having belonged to the original rope had been sold to a dealer in Singapore. This dealer, a man of doubtful character, was traced to Paris in early 1911. When the investigators found him to ask questions, they made sure to keep their pistols within easy reach.

The dealer claimed he had already sold the pearls, but gave investigators the name of the man who had sold the dealer the pearls. He was Paul de Boseck, a former wharfinger (owner), who had been working in Bangkok at the time the box containing the jewellery arrived. The box was in his possession for about five hours before being delivered to the Grand Palace.

Investigators soon learned de Boseck had sold a pair of the distinctive pearls to a bookmaker in Singapore. They travelled to Singapore and interviewed the bookmaker who told them he had already sold the two pearls to another bookmaker, who took them to Australia. This second bookmaker was found and the pearls brought back to Singapore where a director of the Association then purchased the pearls and positively identified them as having belonged to the original rope. He secured an arrest warrant for Paul de Boseck and the hunt was on.

The Association investigators traced de Boseck first to Batavia in the Dutch East Indies and then Ceylon, but lost his trail. That was in June 1911. In December a contact in the Straits Settlement (Singapore) government told investigators de Boseck was in England.

He was traced to an address in London and on 4 January 1912 Paul de Boseck was arrested by London police led by Detective Chief Inspector Bower.

Formally identified as Jules Paul de Boseck, alias Paul de Boseck (but also spelled Bosach and Debusick in some accounts), the alleged thief was a tall, slim 31-year-old (although other accounts stated he was 32) journalist. He had lived and worked in Bangkok as well as Singapore, but it would later be revealed he had led a something of a double life.

De Boseck was remanded under the Fugitive Offenders Act and charged with receiving jewellery which had been stolen at Bangkok. He submitted a written statement to the court noting he was known in Bangkok as lending money on goods and jewellery.

At his first hearing before a magistrate at the Bow Street courts in London, de Boseck was not represented by legal counsel. Inspector Bower, in the witness box, was asked by de Boseck, “Are you speaking of the two pearls I gave a bookmaker named Cohan or Cowan at Singapore in settlement of a debt?”

The police officer replied that he was, at which point de Boseck claimed he didn’t know the pearls were stolen.

Bower replied, “It is alleged you gave a bookmaker at Singapore one or more of those stolen pearls. One of those pearls has been identified as a portion of some valuable jewellery which was handed to you when you were at Windsor’s Wharf, at Bangkok, to forward to the Queen of Siam.”

De Boseck countered by saying a large number of cases of jewellery went through his hands while he was in Bangkok. Bower then asked, “…do you wish to tell me whom you got them from?” The defendant said he needed to talk with his solicitor first.

De Boseck then attempted to regain the initiative by adding that when he lived at one of his three known addresses in England he went by the name of Charles Chilsworth. He claimed he adopted this name “when making enquiries respecting a political offence in Java [then part of the Dutch East Indies] and I retained it in all correspondence in connection with that case. I placed the result of my enquiries before the Chinese Minister at The Hague, and corresponded with him always in that name.” The use of a pseudonym and reference to a clandestine inquiry reaching to the highest levels seemed intended to cast de Boseck in a Sherlock Holmes-style light.

He ended his defence by saying, “I parted with the pearls quite openly at Singapore, and had a receipt for them, but I think I destroyed it when I left Singapore with all other papers relating to my racing there. The receipt contained the weight and description of the pearls.”

Despite his defence, de Boseck was committed to be extradited to the Straits Settlement for trial and left Britain in April 1912. Arriving in Singapore he duly went to court.

Between that first hearing in February 1912 in London and his trial in Singapore, de Boseck refined his story. He claimed a steamer’s clerk who had lost heavily at gambling applied for a loan of 2,000 ticals, using a small box of pearls as security. De Boseck claimed he loaned the Chinese man just 920 ticals and received a receipt for 1,000 ticals. The following day the Chinese man told de Boseck he had lost all this money and asked him if he would buy the pearls. De Boseck claimed he asked the Chinese man where the pearls had come from, and he admitted they had been stolen, but did not say who the rightful owner was.

In his statement to the court de Boseck wrote, ‘I understood [the pearls were] part of a cargo. I gave him another 500 ticals, and the pearls became mine by purchase. My object in not informing the police of the occurrence was threefold – (1) I feared the worry and annoyance the matter would cause me, as I was in a very bad state of health. I was suffering from facial paralysis and brain trouble, due to the climate, opium, and other causes; (2) it was only a little while back that I had made a continued attack in the press on the police and the rottenness of the system. This caused a radical change to be made, one of the Royal princes who was then in charge being transferred to another department; (3) it was a notorious matter that stolen property was dealt with with immunity, the native police usually retaining it, when seized, for their own private benefit, and rarely restoring it to the rightful owners.’

With what was essentially a very weak defence, it was no surprise de Boseck was found guilty at the end of May 1912 and sentenced to two years in prison for possession of stolen property. It was only with the conviction of de Boseck that the £10,000 insurance money was paid to the Association of Diamond Merchants, almost three years following the theft.

In the end, only the two pearls sold by de Boseck in Singapore were ever recovered from the original necklace of 252. The remaining 250 are now scattered all over the world.


The Paknam Incident and its ramifications, 1893


Auguste Pavie, looking more like an Impressionist painter than a scheming diplomat.

Auguste Pavie, the French Charge d’Affaires in Bangkok, was a man with a mission. As he saw it, France’s growing empire in Indochina, currently centred on Vietnam, would be greatly enhanced if Siam were somehow incorporated.

As those charged with administering the Indochinese empire looked westward they saw an opportunity to take Laos out from under Siamese overlordship and, at the same time, precipitate a confrontation which might allow Siam itself to fall into French hands. Their only concern was the stance which might be taken by Britain.

The pretext for the ensuing crisis came when France claimed the eastern boundary of their occupied state of Annam (Vietnam) was marked by the Mekong River. Siam countered and said their eastern border was a ‘chain of mountains parallel to the seaboard.’

On 14 March, Auguste Pavie was instructed to demand Siam’s immediate withdrawal from the left bank of the Mekong and seek compensation for French subjects whom France claimed had suffered damages. At the time, the French gunboat Le Lutin was anchored in Bangkok, as a visible threat.


French gunboat Le Lutin, anchored in Bangkok.

To reach the Bangkok roadstead it is necessary for vessels to sail into the mouth of the Chao Phraya River, and as early as the reign of King Rama II (1809-1824) strategists were aware of the importance of the seaport of Samut Prakan, situated at the entrance to the river on the Gulf of Thailand.

In 1819, the king, in conflict with Vietnam and worried about a possible seaborne attack, ordered the construction of six forts in the area around Paknam. Three of the forts were completed over the next three years; the remainder were finished during the reign of King Rama III.

To further strengthen the seaward defences, the Phra Chulachomklao Fort was constructed on the west side of the Chao Phraya River at the entrance to the estuary, and designed to command the river mouth and for a distance of two kilometres upriver. Commanded by a Danish captain, the Phra Chulachomklao Fort was only completed in April 1893.

On 3 April a French military column reached Stung Treng, on the Cambodian side of the Mekong. The 14-man Siamese post at Stung Treng retreated without firing a shot. Two days later the French took possession of nearby Kong island.

At the same time, King Chulalongkorn made a decision to fight rather than meekly submit to the French and issued orders for three new forts to be built on the Chao Phraya. He also hoped to purchase three warships and expand the army, sending forces to bolster the garrison at the gulf port of Chantaburi (Chantaboon).

Pavie, alarmed by these preparations, advised an immediate resolution of the crisis by way of military action. The French Foreign Minister, Jules Develle, ordered Admiral Edgar Humann, the commander of the French Far Eastern Naval Division, to concentrate his nine warships off Saigon. Pavie considered this presented the ideal moment to turn Siam into a French protectorate. As he noted, if Siam resisted, ‘A protectorate over Siam will be our compensation. If we neglect such an opportunity now, will we ever be offered another to round off our Indochinese empire?’

The stakes increased when the Thais regained Kong island, capturing a French captain. Then, the French Inspector of the Civil Guard was ambushed and killed. France claimed he had been murdered.

In June, the French sent a special envoy to Bangkok with instructions to withdraw their entire diplomatic mission and, with the help of the governor-general of Indochina, send warships to blockade the mouth of the Chao Phraya if Siam refused to recognise the French claim to the left bank of the Mekong and pay compensation for a series of incidents stretching back to 1891.

At the same time, British Prime Minister Lord Rosebery sent two gunboats to Bangkok, ostensibly to provide protection to British citizens. In reality, as Lord Kimberley, the Secretary of State for India, wrote privately to Rosebery, sending gunboats was ‘the natural mode of demonstrating…’

On 10 July, France informed the Siamese Foreign Minister, Prince Devawongse, the French gunboats Inconstant and Comete would, in accordance with Article 15 of the Franco-Thai Treaty of 1856, cross the bar and anchor at Paknam before proceeding to Bangkok. Prince Devawongse issued a protest at this and asked that further negotiations take place.

Although Pavie ostensibly agreed he sent Admiral Humann orders for the warships to proceed to Bangkok. The gunboats, with the Jean Baptiste Say, a small French merchant ship as a pilot, sailed towards the entrance of the Chao Phraya on 13 July.

Over the preceding years King Chulalongkorn had spent some time strengthening his navy, bringing in foreign expertise. At least 25 Danish officers were then serving in the Siamese navy and the commander at Paknam was Vice Admiral Andreas du Plessis de Richelieu. He later became the commander-in-chief of the Royal Siamese Navy.


Chulalongkorn, King Rama V

Siam’s not-so-secret weapon were seven British-made Armstrong six-inch ‘disappearing’ guns at the Chulachomklao Fort. These were state-of-the-art cannons loaded while hidden behind bunkers but popped up hydraulically to fire. The guns in both Phra Chulachomklao Fort and Phissuasamut Fort opened fire on the French. Siamese gunboats also joined the assault.

The Jean Baptiste Say was run aground and her crew made prisoner while the Siamese steel cruiser Makut Rajah Kumar suffered damage.

The Inconstant and Comete made it through the gauntlet, suffering some damage and casualties, with three sailors killed.

They sailed up to anchor opposite the French Legation where they allegedly trained their guns on the Royal Palace. The Siamese lost between 15 and 25 dead in the battle.

The delightfully-named Walter Christmas, who held the rank of captain, later described the action, saying it was ‘just a hodgepodge of hopeless ships, useless guns, and incompetent crews, commanded by men who, however stout and resourceful in other fields, for the most part were without knowledge in military skills.’ Christmas claimed he fired his cannon four times, but when he tried to fire a fifth time, ‘it collapsed’.

On 20 July, France issued an ultimatum – with a 48-hour deadline – demanding Siam formally recognise the rights of Annam and Cambodia over the left bank of the Mekong and the islands in the Mekong; withdraw Siamese troops from the left bank within one month; pay compensation for damage inflicted on French troops and warships; punish Siamese offenders and pay compensation to the families of French subjects adversely affected; pay an indemnity of two million francs to French subjects for various claims and deposit the sum of three million francs as a guarantee Siam would abide by these demands.

The French had also occupied Koh Si Chang, opposite Sri Racha, and on 22 July Admiral Humann arrived to oversee future operations.

Siam was forced to accept the French ultimatum but asked that the rights of Annam and Cambodia over the left bank of the Mekong be limited to the 18th Parallel. Siam also sought the joint use of the islands in the Mekong. The French rejected the Siamese proposals, withdrew their consular officers from Bangkok, and blockaded the Gulf of Thailand, using Koh Si Chang as their headquarters.

The incident caused relations between France and Britain to grow tense, although the British were unwilling to risk a war over the independence of Siam, despite the tacit support of Germany. Instead, the British advised Siam to accede to French demands to avoid an all-out conflict. Siam conceded and on 3 August the French lifted their blockade.

Siam subsequently signed a treaty with France on 3 October 1893. Siam renounced her claim to the left bank of the Mekong as well as the islands in the river; agreed not to construct any fortifications or military establishment within a 40-kilometre radius of the right bank of the Mekong and gave the French the right to establish consulates wherever it deemed appropriate, (such as Khorat and Nan). The French also demanded the right to occupy Chantaburi until Siam complied with all the terms of the treaty.

The compensation demanded by France amounted to three million francs and paid for out of Siam’s foreign reserves as well as a contribution by King Chulalongkorn and some of his relatives. The silver was delivered to the Le Lutin.

On 4 December, an Anglo-French agreement was signed which ostensibly guaranteed Siamese independence. France and Britain agreed to maintain the region as a neutral zone using the Mekong as a boundary line. In a subsequent declaration, the British and French agreed not to send troops to the region between the Mekong and the Tenasserim Mountains without the prior consent of the other party and stated French and British nationals residing in the region would not receive special privileges or benefits which nationals of the other party did not receive.

The agreement, reached without the involvement of Siam, basically meant neither Britain nor France would impinge upon Siamese sovereignty without the prior consent of the other party. It in no way guaranteed Siamese independence, merely indicating the British and French were not prepared to go to war over Siam.

In January 1896, a second Anglo-French agreement regarding Siam was signed. The British abandoned their claims to any territory east of the Mekong, thereby making the river the official border between Laos and Burma. In return, the French agreed to accept the independence of Siam.

Cementing relations further with the British, Siam signed a secret agreement with Britain in April 1897 whereby Siam agreed not to cede any territory or rights south of the 11th Parallel on the Malay Peninsula without prior British consent. In return, Britain promised to support Siam against any attempts by a third power to assume control in the Malay Peninsula.

The French continued to occupy Chantaburi until 7 October 1902 when an agreement was signed with Siam ceding two southern Lao provinces. The agreement was not ratified by the French parliament and French troops occupied Trat.

The seven Armstrong guns that participated in the action against the French in 1893 were still in working order 105 years later when they fired a seven-gun salute to celebrate the fort’s anniversary. Since the Paknam Incident, they have never fired a shot in anger.