Text & photographs by Tricky Vandenberg - March 2011
Updated April 2011
Detail of de La Loubere's book
There were basically four Siamese coins used as standard currency for trade in
Ayutthaya in the 17th-18th century, being the Baht, the Salueng, the Fueang and the
Song Phai. All these coins were in silver and had their specific weight. There seems to
have been two other coins, but these were not found very common. Gijsbert Heeck
mentions a fifth coin, being half a Baht: "The Ticals are sometimes divided in half: but
these coins are rarely seen." [1] Nicolas Gervaise speaks about the existence of a sixth
denomination, being worth half a Song Phai. [2] On the latter two denominations, I could
not find any data  until today. Find here under a description of the Siamese coins traded
in the Late Ayutthaya Period.

All Siamese coins used throughout the Ayutthaya period were silver bullet money, called
Phot Duang (พดด้วง).  It was used in Siam as currency in trade transactions for 500
years, until it was abandoned in 1904, in the reign of King Rama V. [3]

The Phod Duang was made by hammering a small silver bar into a ball in a mold and
minted the silver ball with two seals to certify it was officially sanctioned. The state's seal
was a wheel (in different variants) representing the Dharmachakra or the Wheel of the
Buddhist Law, and the King’s seal was a lotus bud (also in different variants). The latter
was altered every time a new king came on the throne. King Ramathibodhi I's seal was
exceptionally a conch shell. [3]

Heeck described in 1655 the coin as a
"long piece of refined silver, beaten almost
completely round, and stamped with a small figure such as an elephant, deer, or
the like
". [1] Gervaise in 1688 put it as follows: "It is round on one side like a musket-
ball and on the other side flat and split down the middle about half-way across.
Near the slit is the design of a heart or of a small triangle and on the back is a
small circle.
" [2]

The Phot Duang had its proper value in silver and as such counterfeiters were as much in
existence in those days as at present. The first king of Ayutthaya, King Ramathibodhi
proclaimed the Robbery Act drafted in 1360, containing a provision concerning forgery:
One who produces false coin from any metal, or falsifies existing coin, if found
guilty, I shall have his fingers severed so that he may never again hold a hammer
or pliers
. [3]

Van Vliet wrote:
"The common people are very curious about such seals, so that
one has great trouble in paying it out, for out of ten pieces they sometimes do not
want to take a single one, not because the silver alloy is not good, but because the
seal of the king is not according to the rule"
. [4]

Baht (บาท)

The highest unit was the Baht, commonly called Tical. The Dutch traded 1 Baht for 30
stuivers (a silver coin worth 5 cents). Exchanges in Ayutthaya and places down stream
such as Bangkok were not the same for the Dutch. Downstream the Baht was changed
against 48 stuivers or 8 Dutch Shilling. The French exchanged the Tical against 33 Sous
and 6 Deniers [2] or 37,5 Sous (before called Sol). [4]

A unit of currency equal to 100 Setang.

The Tical or Baht was also a weight. Following de La Loubère it weight 768 grains of
whole rice. [5]

Salueng (สลึง)

The second silver coin - with silver as pure as the Baht - and of more or less the same
design, is called the Salueng. The Salueng was a quarter of a Baht; four Salueng made up
one Baht. The Europeans called it commonly the Maas; Maion for the French. [1] [2]

The French traded the Maion at eight sous and four deniers. [2] The Dutch
exchanged the Maas for 7,5 Stuivers [4]

A unit of currency equal to 25 Setang

Fueang  (เฟื้อง)

The third coin is the Fueang. It was also of silver with a weight little less than 2 grams. [1]
The Fueang was worth 1/8 of a Baht and half a Salueng.

The Dutch valued it at a little less than 20 cents [1] or 3,75 Stuivers [4]. The French
traded it for four Sous and two Deniers [5]. De La Loubere set its valua at four "Payes".
[5] (1)

A unit of currency equal to 12,5 Setang.

Song Phai

The fourth and last silver coin was the Song Phai. Van Heeck states that it was rarely
seen. The Song Phai stood at half a Fueang and was worth 300 cowries. [1]

The French valued the "Sompaie" at two Sous and one Denier. [2]

Song Phai means literally two "Phai".

A unit of currency equal to 6,25 Setang.

Bia (เบี้ย)

Next to coins which were merely used by the traders, common people widely used
cowry shells as currency to buy daily commodities. Cowries were used as a medium of
exchange since the dawn of Chinese civilization. The word “cowry” or “kauri” finds it
origin in India. The "kauri" was used as money on the sub-continent as early as 900 A.D.
The Siamese called it "Bia".

Engelbert Kaempfer noted in 1690: "A Pynini contains an uncertain number of Bijas, by
us called Cowers, being a small white, or yellowish Shell of the Concha Veneris kind,
which I have described in its proper place. The Cowers differ very much in value; One
may buy for a Phuang from 500 to 800. They are imported in great quantities from the
Maldive Islands." [6]

Kaempfer's identification of the shell would be incorrect today. The cowry was
scientifically named after its use - Monetaria moneta (Linnaeus, 1758) or Cypraea
moneta (Linnaeus, 1758), the money cowry. It is a broad shell with knobbly outline and
raised dome, up to 4 cm; colour creamy, yellowish or pale green, occasionally with three
faint darker bands. [Ref: World Register of Marine Species] The cowry is very common
in the shallow waters of the Indian Ocean, where it is an herbivore that can be collected
on rocks. Many cowries were gathered in island groups such as the Maldives and the

There was as thus a lively trade in these shells throughout South and Southeast Asia.
Much wanted by the Ayutthaya Court, many cowry shells were imported by the Dutch
East India Company, mostly from the Maldives, but also from the waters around
Kalimantan. [7]

Van Vliet wrote "With 5 to 20 of these shells, or even with less, the people may buy on
the market sufficient supplies for one day". [4]

300 cowries were valued 1 Song Phai or half a Fueang [1] (2)


To make the bullet money, silver was needed by the Ayutthayan court in large quantities.
In the 17th century much of the silver came from Japan, which appeared to have been
rich in silver.

In 1617 the English factors at Siam, in exchange for their cargo, requested a return from
Japan in silver coins. The English East Indian Company in Hirado reported it was
unlawful in Japan to stamp any coin, but that it was permissible to melt silver into bars.
Apparently there was as thus a vivid trade in silver. [8]

In 1690 Kaempfer noted that: "All the Silver money of Siam is coined of Dutch Crowns
[Ducaton], which are for this purpose coined in Holland, and imported by the Dutch East
India Company at seven shillings the Crown". [6] We can deduct from this that at the end
of the 17th century the traffic of "silver plate" from Japan was practically ceased and the
Dutch took over this market. [8]


(1) A Phai or "Paye" like the French wrote it, was valued 2 clams. The clam was thought
to weigh 12 grains of rice. [3]. Contrary, Nicolas Gervaise wrote:
"Formerly, there
was a fifth denomination worth half a sompaie, but it is no longer legal tender in
the kingdom and in place of this, the lowest in value of their old currency,
equivalent to our doubles and deniers in France, the Siamese now use certain
shells which they call bia
." [2]

(2) Van Vliet wrote:
"600 to 700 of these are worth one foeang" [4] Gervais put it as
follows: "
There are eight hundred of these to the Fouang, so that for fifteen francs
one can get more than one can carry
". [2]


[1] A Traveler in Siam in the Year 1655: Extracts from the Journal of Gijsbert Heeck -
Barend Jan Terwiel (2008) - Silkworm Books - Page 42 -43.
[2] The Natural and political History of the Kingdom of Siam - Nicolas Gervaise (1688)
- White Lotus - Page 101-102.
[3] Discovering Ayutthaya - Charnvit Kasetsiri & Michael Wright (2007) - Page 274-
[4] Van Vliet's Siam - Chris Baker, Dhiravat Na Pombejra, Alfons Van Der Kraan &
David K. Wyatt (2005) - Silkworm Books - Page 171-172.
[5] A New Historical relation of the Kingdom of Siam by Monsieur de La Loubère -
John Villiers (1986) White Lotus - Page 164.
[6] The History of Japan: Together with a Description of the Kingdom of Siam -
Engelbert Kaempfer - John Gaspar Scheuchzer (1906) - page 67.
[7] In the King's Trail - Remco Raben & Dhiravat na Pombejra (1997) - The Royal
Netherlands Embassy, Bangkok.
[8] English intercourse with Siam in the 17th Century. - John Anderson (1890) - page 68.
(Detail of de La Loubère's book)
Cowry shells excavated at the Portuguese Settlement
Silver coin of 1 Fueang, excavated at the Portuguese settlement
(Silver coin of 1 Fueang, excavated at the Portuguese
settlement - Courtesy Sam Chao Phraya Museum)
(Cowry shells excavated at the Portuguese Settlement -
Courtesy Chao Sam Phraya Museum)