Siam, Syām, Sayām: The Names of Thailand Until 1939
What is Siam, and why did Thailand stop using the name? For centuries the country was known to the outside world as Siam, also written Syām or Sayām (สยาม). It was officially changed to Thailand in 1939, briefly restored between 1945 and 1949, and then dropped for good.
What Does Siam Mean? The Origin of the Name
Scholars have not settled where the word comes from. The main ideas are:
- Sanskrit origin: śyāma, meaning dark, brown or golden. Some theories tie it to skin colour, others to an auspicious meaning.
- Neighbouring languages: Syam appears in Khmer inscriptions of the Angkor period and in Cham inscriptions from around the 11th to 12th century, used for people west of the Khmer realm. Reliefs at Angkor Wat also show “Syam” soldiers.
- Links to other Tai groups: some proposals connect the word to names such as Shan and Ahom, though the evidence is thin.
The name was therefore an outsiders’ label before the people of the kingdom used it for themselves. “Siam”, “Syām” and “Sayām” are simply different ways of writing the same word.
How the World Came to Call the Country Siam
- Chinese sources used Xianluo (暹羅). A common explanation joins “Xian” (Siam, associated with Sukhothai) and “Luo” (Lavo), though that origin is debated.
- The Portuguese wrote Sião. They were the first Europeans to deal with Ayutthaya, in the early 16th century. Dutch, English and French writers later adopted “Siam”.
- Malay also used Siam.
At home, the Ayutthaya kingdom was formally known as Krung Si Ayutthaya, while “Siam” appeared in inscriptions, royal letters and foreign documents. By the Bangkok period, and especially after King Mongkut signed the Bowring Treaty in 1855 as “King of Siam”, Siam had become the country’s name on the international stage.
Why Siam Changed Its Name to Thailand in 1939
On 24 June 1939, the government of Field Marshal Plaek Phibunsongkhram officially renamed the country “Prathet Thai”, or Thailand. The change fitted a nationalist agenda that stressed Thai identity. “Thai” is often explained as meaning “free” or simply the Tai people, although linguists still debate that meaning.
The new name put the Thai people, rather than a label given by outsiders, at the centre of the country’s identity.
Siam to Thailand: A Timeline
- Before 1939: Siam is the country’s official name in international use.
- 24 June 1939: the name officially becomes Thailand.
- 1945: after the Second World War, the name Siam is restored for a short time.
- 11 May 1949: the country becomes Thailand again, and the name remains in use today.
Where the Name Siam Still Appears Today
Siam is no longer the country’s name, but it is far from forgotten. You will find it in Bangkok’s Siam Square, in Siam Commercial Bank, in the Siamese cat, and in the phrase “Siamese twins”, made famous by Chang and Eng Bunker, who were born in Siam in the 19th century.
Siam FAQ: Your Questions About the Name Answered
There is no settled answer. One theory links the name to the Sanskrit word śyāma, meaning dark, brown or golden. Another points to the word Syam in old Khmer and Cham inscriptions, where it referred to people living west of the Khmer realm.
Yes. They are different spellings of the same name. “Siam” is the familiar English form, while “Syām” and “Sayām” are scholarly transliterations of the Thai spelling สยาม.
The official change to “Thailand” (Prathet Thai) came on 24 June 1939, under the government of Field Marshal Plaek Phibunsongkhram.
Yes, briefly. The name Siam was restored in 1945, after the Second World War. The country became Thailand again on 11 May 1949, and the name has not changed since.
The name survives in Siam Square, Siam Commercial Bank, the Siamese cat and the term “Siamese twins”, which became widely known through Chang and Eng Bunker, who were born in Siam in the 19th century.
Conclusion
Siam, Syām and Sayām are one name written in different ways. It tells us how Thailand was seen from the outside, and how the country chose to keep, drop and finally replace that name: Siam until 1939, Siam again from 1945 to 1949, and Thailand ever since.
Note: the origin of the word “Siam” is still a scholarly hypothesis, not a settled conclusion.
