Founding of Ayutthaya (1351): U Thong's Siamese Kingdom

Ayutthaya was founded in 1351 by a ruler known as U Thong, who took the royal title Ramathibodi I, on an island where three rivers meet in central Thailand. The city became the capital of a Siamese kingdom that absorbed its rivals, traded with China, India, Japan and Europe, and dominated much of mainland Southeast Asia until its fall in 1767. Its founding marks the start of one of the longest-lasting states in the region’s history.

Background: central Thailand before 1351

In the 13th and early 14th centuries the Chao Phraya basin was divided among several Tai and Mon-Khmer centres. In the north, the kingdom of Sukhothai had been powerful under King Ram Khamhaeng, but it declined after his death. To the south-east, the Khmer Empire of Angkor still claimed prestige but had lost much of its control over the region.

In the lower Chao Phraya basin, towns such as Lopburi, Suphanburi and Phetchaburi grew rich from rice farming and sea trade. Chinese records mention a state called Xian (Siam) sending missions to China from the late 13th century, probably based in this area.

The site of Ayutthaya was not empty. A town sometimes called Ayodhya already existed nearby, and a famous large seated Buddha at Wat Phanan Choeng is traditionally dated to 1324, more than 25 years before the official founding.

The founding

According to the Thai royal chronicles, U Thong founded Ayutthaya in 1351. The Luang Prasoet chronicle, the most precise of them, gives a date equivalent to 4 March 1351. A later legend says U Thong moved his people from an older town because of an epidemic, but this story cannot be confirmed.

The site was chosen with care. The Lopburi and Pa Sak rivers meet the Chao Phraya here, and with a canal the city stood on an island ringed by water. Ocean-going ships could reach it from the Gulf of Thailand, while the annual floods made a long siege very difficult for any attacker.

U Thong named his city after Ayodhya, the capital of the hero Rama in the Indian epic Ramayana. The full name, Krung Thep Dvaravati Si Ayutthaya, also echoed the earlier Mon kingdom of Dvaravati, presenting the new state as heir to older traditions.

Key people

U Thong (r. 1351-1369), crowned as Ramathibodi I, is a figure of uncertain origin. Different traditions link him to the town of U Thong, to Phetchaburi or to a Chinese merchant family. Most historians think he rose through marriage alliances with the ruling families of Suphanburi and Lopburi. Later Thai tradition credits him with some of the earliest laws later preserved in the Three Seals Code.

Ramesuan, U Thong’s son, ruled Lopburi and succeeded briefly in 1369 before giving way to Borommarachathirat I (r. 1370-1388), a member of the Suphanburi family. The rivalry between these two lineages shaped Ayutthaya politics for decades.

Rise to regional power

Within a generation Ayutthaya began to expand. Borommarachathirat I campaigned against Sukhothai and made it a vassal by 1378; it was fully absorbed in the following century.

Ayutthaya also turned against Angkor. After repeated wars, an Ayutthaya army took the Khmer capital in 1431, an event often seen as the end of Angkor’s greatness (see the fall of Angkor). Khmer court traditions, rituals and ideas of divine kingship strongly influenced the Ayutthaya court.

The city flourished as a port. Ayutthaya sent regular missions to Ming China, and merchants from Persia, India, Japan, the Malay world and later Europe settled in their own quarters around the island. By the 17th century European visitors compared it with the great cities of their own continent.

Government and society in early Ayutthaya

Early Ayutthaya was less a single unified state than a network of towns bound to the capital by kinship, marriage and loyalty. Princes of the royal family governed important centres such as Lopburi, Suphanburi and Phitsanulok, and powerful governors could challenge the king. Succession disputes were frequent and often violent.

Kingship drew on several traditions at once. Theravada Buddhism, spread from Sri Lanka and already strong at Sukhothai, was the religion of the court and the people, and kings presented themselves as patrons of the monastic order. Brahmin priests, many of them trained in Khmer traditions, performed royal ceremonies, and the king came to be seen as a semi-divine figure kept at a distance from ordinary subjects.

Over the following century Ayutthaya developed the sakdina system, under which every person was assigned a numerical rank expressed in units of land. Most commoners owed regular labour service to the crown or to a noble patron, which gave kings the manpower to build walls, temples and armies.

Trade and diplomacy

Trade was central to Ayutthaya from the start. The surrounding plain produced rice in large quantities, and the forests of the interior supplied valuable goods such as sappanwood, deerskins, ivory and aromatic woods that were in high demand in China and Japan.

Soon after the Ming dynasty came to power in China in 1368, Ayutthaya sent tribute missions to the new emperors. These missions brought Chinese recognition of the king, valuable gifts and permission to trade, and Chinese merchants became an important community in the city.

The kings also controlled much of the foreign trade directly through a royal monopoly on certain goods, a practice that helped pay for the court and the army.

Myths and facts

It is often said that Ayutthaya was built on empty land in 1351. In fact, archaeological finds and the Wat Phanan Choeng Buddha show an earlier settlement, and the founding date marks the establishment of a new royal capital rather than the first occupation.

The story that U Thong fled an epidemic is sometimes linked with the Black Death, which struck Asia and Europe in the 1340s. There is no evidence connecting the two.

Legacy

The kingdom founded by U Thong lasted 416 years, until a Burmese army destroyed the city in 1767 (see the fall of Ayutthaya). The later Thai capitals of Thonburi and Bangkok consciously modelled themselves on Ayutthaya. When King Rama I built Bangkok from 1782, he reused bricks from the ruined city, laid out the new capital on a river island in the same way, and revived Ayutthaya’s court ceremonies, titles and administrative practices.

In Europe, the kingdom was known as Siam, a name used officially until 1939, when the country became Thailand. For more than four centuries, foreign visitors, diplomats and merchants knew Siam above all through its capital on the Chao Phraya.

The ruins of the old city, including Wat Phra Si Sanphet, Wat Mahathat and Wat Phra Ram, which was built on the site of U Thong’s cremation, were inscribed as the Historic City of Ayutthaya on the UNESCO World Heritage List in 1991.

Timeline

• 1324: Traditional date of the great Buddha image at Wat Phanan Choeng, before the official founding.
• 1351, 4 March: Traditional date of the founding of Ayutthaya by U Thong (Ramathibodi I).
• 1353: Wat Phutthaisawan is built, according to tradition, where U Thong first settled.
• 1369: Death of U Thong; his son Ramesuan briefly succeeds.
• 1370: Borommarachathirat I takes the throne.
• 1378: Sukhothai becomes a vassal of Ayutthaya.
• 1431: Ayutthaya captures Angkor.
• 1767: The Burmese army destroys Ayutthaya.

Why it matters

The founding of Ayutthaya created the core of the Siamese state from which modern Thailand developed. Its position on the rivers and the sea made it one of the great trading cities of Asia, and its court culture, laws and Buddhist institutions remain central to Thai identity.