Ayutthaya Kingdom

In foreign accounts, Ayutthaya was called "Siam" but people of Ayutthaya called themselves Tai, and their kingdom Krung Tai (กรุงไท) meaning 'Tai country' (กรุงไท). The Fra Mauro map of the world, made in circa 1450, features Ayutthaya city under the Latin name "Scierno". This name was derived from the Persian "Shahr-I-Naw", meaning 'New City'. Early Iberian and Italian sources preserve several related variant spellings that also appear to refer to Ayutthaya, including forms such as Cernouem and Cernomé in Portuguese and Spanish compilations, and Xarnauz and Sarnau in other accounts. A handwritten nautical chart attributed to Vesconte de Maggiolo (c. 1508) labels Ayutthaya as Zerena. Some early Portuguese descriptions characterize Xarnauz as a "Christian" kingdom, a wording that may reflect European assumptions about non-Muslim states rather than local religion.

It was also referred to as Iudea (and Iudiad) in a c. 1662–1663 bird's-eye view painting of Ayutthaya attributed to Johannes Vingboons, commissioned by the Dutch East India Company. Alternative spelling is Iudia in a 1683 illustration by Alain Mallet.

The capital city of Ayutthaya is officially known as Krung Thep Dvaravati Si Ayutthaya (กรุงเทพทวารวดีศรีอยุธยา), as documented in historical sources. The Dvaravati element of that style is attested from the Ayutthaya period into the early Rattanakosin period. The preambles to three sections of the Three Seals Law, those on witnesses, on royal legislation, and on ordeal by water or fire, give the capital as Krung-deb-dvāravatī-śrī-ayudhyā-mahātilakabhaba-nabaratana-rājadhānī-purīramya (กรุงเทพทวารวดีศรีอยุธยา มหาดิลกภพ นพรัตน์ราชาธาณีบูรีรมย์). The same pairing appears in a letter from the governor of Tenasserim to the Danish court in 1620, in the Thai text of the 1664 treaty with the Dutch East India Company, in a Pāli letter to Kandy in 1757, in the chronicle compiled by Somdet Phra Phonarat at Wat Pho, and as late as 1842 in an inscription set up in Cambodia by Chaophraya Bodindecha.

The name was not used consistently, however: other sections of the same law code use forms of Ayutthaya without Dvāravatī, as do the Ratanabimbavaṃsa (1429), the Jinakalamali (c. 1516), the Yuan Phai and the Dansai inscription of 1560, and Prince Dhani Nivat, whose 1939 study in the Journal of the Siam Society remains the standard treatment of the question, observed that most official and literary works of the Ayutthaya and Bangkok periods name the capital simply as Ayutthaya or Krung Rattanakosin. Skilling has accordingly treated it as an open question whether the surviving instances preserve a continuous memory of Dvaravati or represent a later literary and diplomatic revival of the name. Even though Baker and Pasuk regard the use of Dvāravatī in Ayutthaya's official titles as a possible invention of tradition, a Burmese inscription on a bronze gun captured at the city's fall in 1767 also identifies Siam as Dvāravatī. This provides independent evidence for the use of the name for Siam at the end of the Ayutthaya period.

In the early second millennium, the lower central plain was anchored by Lavo to the east and Suphannabhum, a former Dvaravati centre, to the west, with Chen Li Fu between them. Lavo, conventionally described as under Angkorian suzerainty, occupied the eastern basin, while Suphannabhum in the west shows Angkorian cultural influence that need not imply direct political or military control. Evidence for varying degrees of Angkorian political and cultural involvement includes Suryavarman I's campaigns in the Kra Isthmus, Khmer-influenced architecture, the place of local elites in the Khmer hierarchy, and Jayavarman VII's patronage of cities in Ratchaburi and Phetchaburi. Kanjanajuntorn and colleagues nonetheless find the strongest Bayon influence in the Mae Klong valley, at Mueang Kosi Narai, Wat Maha That Ratchaburi and Wat Kamphaeng Laeng, while Dvaravati forms persisted along the Tha Chin, including Suphanburi. The evidence is consistent with Angkorian influence in the Mae Klong valley, but suggests selective borrowing rather than imposition.

Chen Li Fu, known from Chinese records and placed by Songsiri at Phraek, occupied the central position between Lavo and Suphannabhum. Songsiri notes, however, that archaeological evidence has not established when the settlement became its seat or whether it succeeded an earlier inland centre. It administered more than sixty settlements, appears in Chinese merchant records by about 1103–1115, and sent embassies to the Song in 1200, 1202 and 1205. Its ruler used the Angkorian title kamretan-an, and Chinese officials eventually excused the polity from further tribute. Songsiri proposes that after the first half of the 13th century its network developed into Suphannabhum, incorporating settlements around the Khwae rivers and the western basin, while Sing Buri and Phrom Buri belonged to the Lavo network.

Angkorian relationships with the basin polities have increasingly been interpreted in terms of a mandala, in which titles, cultural forms, and religious gifts circulated without necessarily implying sovereignty. The Preah Khan inscription of Jayavarman VII names cities of the western basin, including Suphanburi as Suvarnapura, Phetchaburi as Srijayavajrapuri, Mueang Kosi Narai as Samphukapatthana, and Ratchaburi as Srijayarajapura, but records no authority over them. Its record of sending Jayabuddhamahanatha images to western polities, together with the absence of Angkorian hospitals and fire houses west of Prachinburi, likewise suggests cultural diplomacy rather than direct rule.

The material and epigraphic record is similarly regionalized. Mueang Sing follows the Bayon style of Jayavarman VII's reign, but local irregularities and later inscriptions suggest local construction and modification rather than a wholly Angkorian foundation. Inscriptions from the basin, including the Dong Mae Nang Mueang inscription (K. 766) of 1167, the Phra Phuttharup Nak Prok inscription (K. 995) of 1213 and the Mueang Sing inscription, contain Thai lexical elements and script forms distinct from those of Phimai, Surin, Buriram and Angkor.

Titulature alone does not establish subordination. Wolters inferred from the Khmer title Kamrateng used by the rulers of Chen Li Fu that the polity was a Khmer dependency, but the comparable title used by the ruler of Phetchaburi in 1295, does not by itself demonstrate Khmer control. Songsiri notes that Chinese records apply kamrateng to rulers of Sukhothai, Phetchaburi and Chen Li Fu alike, whereas the settlements dependent on Chen Li Fu had rulers who did not bear the title. Charnvit Kasetsiri sees a Khmer-dominated east and broadly independent west as early as the eleventh century, while Vickery dates Angkor's loss of control later and interprets the fragmentation as part of internal Angkorian politics. By the mid-thirteenth century, however, the region's political autonomy is clearer: envoys sent to China presented their states independently, while local art styles increasingly diverged from the classical Khmer manner.

On Kasetsiri's account, Ayutthaya emerged from the merger of four port polities of the lower basin: Lopburi, Suphanburi, Ayodhya and Phetchaburi. Each had sent missions to China in its own name, including Suphanburi to the Song in 1180 and Phetchaburi to the Yuan in 1294, with further missions to Vijayanagara between 1400 and 1500.

The city that became Ayutthaya is known in the Thai chronicle tradition as Ayodhya (อโยธยา). The Northern Chronicle places its earliest settlement in the in the 930s–940s in the area around the Nong-sano Lake (หนองโสน), founded by Phuttha Sakhon (พระมหาพุทธสาคร), whose lineage was associated with Bang Pan in present-day Kamphaeng Phet. The settlement was then called Mueang Nong-sano (เมืองหนองโสน), and his son succeeded him in 974.

The son was subsequently deposed by Sindhob Amarin, also known as Phraya Kreak (พญาแกรก), ruler of Phraek or Indaprasthanagara, who brought Mueang Nong-sano under his authority; Lavo is likewise said to have come under his rule.

According to a later chronicle tradition, the Lavo court moved to the site in the 1080s. Narai I, son of Chandrachota of Lavo, was enthroned at Lavapura in 1082 and subsequently transferred his seat to Mueang Nong-sano, renaming it Ayodhya; the older capital thereafter became known as Lopburi. Proposed explanations for the move include changes in the course of the Lopburi River, political or religious divisions within the Lavo elite, and the recovery of Lavo from Angkorian influence by forces associated with Suphannabhum and Haripuñjaya.

Narai I died in 1087 without an heir, and nine amatya clans contested the throne until Phra Chao Luang prevailed in 1089. He married his only daughter to Sai Nam Peung, whose descendants are said to have ruled Ayodhya until 1351. A second line is interpreted by scholars as becoming connected to Ayodhya in 1205, when Uthong II, son of Phanom Thale Sri of Chen Li Fu–Phetchaburi, married a daughter of Dhammikaraja, who belonged to the earlier line. His descendants subsequently ruled Ayodhya for more than a century.

The three remaining polities of Kasetsiri's account had ruling lines of their own. At Suphannabhum, Pansa, a son of Balaraj of Dvaravati Nakhon Pathom, is said to have ruled at Phanthumburi (พันธุมบุรี) on the left bank of the Tha Chin before moving his seat to Uthong, dying in 1006, and was followed by Ramapandita (1006 – c. 1046) and Anga Indra (c. 1046–1081). The throne then passed to Kar Tayy, a Pagan noble, who ruled until about 1121 and moved the principal centre back to Phanthumburi, thereafter called Songphanuri. Mueang Uthong was abandoned during the 12th century, and Songphanuri stood vacant until Uthong I took it in 1163, conventionally the start of the Xiān period at Suphanburi. Baker and Pasuk attribute the abandonment of Mueang Uthong to a shift in the river that cut the town off from easy access to the gulf, and suggest that its people moved some 30 kilometres north-east to Suphan Buri, whose strictly rectangular moat of 1.9 by 0.7 kilometres and central relic stupa in Angkorian style may both date to the 12th century.

Phrip Phri, at present-day Phetchaburi, was re-established in the same generation by Uthong I's brother Phanom Thale Sri, dated 1157/58 in the Instructions Given to the Siamese Envoys Sent to Portugal of 1684 and 1188 in Du Royaume de Siam. The 1684 Instructions count four kings over 163 years, the last of them Uthong V. Phanom Thale Sri extended his reach north to Mueang Phraek in 1180, appointing his preceptor to govern, over territory that also covered the region proposed for Chen Li Fu; to the south, a dispute with Tambralinga in 1196 ended in negotiation and a lasting dynastic tie, which bore fruit late in the 13th century when princes of Phetchaburi revived that polity after its collapse, thereafter known as Nakhon Si Thammarat. Both were tributaries of Sukhothai between about 1283 and 1298 on the Ram Khamhaeng Inscription, and both broke away after Ramkhamhaeng's death. Phrip Phri's standing in Chinese eyes is telling: its ruler bore the Khmer-derived style Gan-mu-ding, yet the texts call the place chéng (城, "city" or "city-state") rather than guó (國, "country").

Lavo followed a separate course after Narai I moved the seat. Shridhammatripitaka of Ngoenyang Chiang Saen is thought to have seized Lopburi in 1106, after which it passed to Sri Dharmasokaraja I of Tambralinga–Suphannaphum in the 1110s and fell under Angkor in 1117; it recovered enough independence to send tribute to China in 1155, was retaken by Angkor under Jayavarman VII, and late in the century was governed by Nripendravarman, later enthroned at Angkor as Indravarman II. Five further tribute missions went to China between 1289 and 1299, and by the 1320s the seat is thought to have been held by the maternal grandfather of Ramesuan, Uthong V's son, which accounts both for the marriage by which Uthong V acquired Lavo and for Ramesuan's retreat there in 1370. Lavo was not fully incorporated into Ayutthaya's political order until 1388.

Through this period the polity appears in foreign sources as Xiān (暹), from which the name Siam derives. The earliest surviving notices are Vietnamese. The Đại Việt sử ký toàn thư records merchants from Xiān reaching Hǎidōng in 1149 and seeking to trade and establish a post at Yún tún (雲屯), modern Vân Đồn, with further contacts in 1182, 1241, and 1360. In 1313–1315 Xiān attempted to attack Champa but was repulsed after Đại Việt intervened. The Ma Nhai inscription of 1335 likewise names Xiān among the polities bringing local products to the Trần court.

Chinese sources likewise place Xiān among the independent polities of mainland Southeast Asia. The Yuan sent a mission to Xiān in 1282, although its commander was killed in Champa before reaching his destination. Xiān sent its first embassy to the Yuan in 1292; after initial demands for submission, its king, Gan-mu-ding, appeared in person with tribute in 1295. G. H. Luce identified this ruler with the king of Pi-ch'a-pu-li, that is Phrip Phri. Further embassies followed through the early 14th century, while Lavo sent missions to the Yuan independently. Wang Dayuan's Daoyi Zhilue of 1351 describes Xiān as a trading polity supplying tropical products, while Zhou Daguan's account of Angkor in 1296–97 reports large numbers of Siamese at Yasodharapura, influence over Lavapura, and repeated conflict between Siamese and Khmer interests.

The identity of Xiān has been interpreted in several ways. Older scholarship identified it with the Sukhothai Kingdom or Suphanburi, while Chris Baker and Pasuk Phongpaichit argue that it referred to Ayodhya, noting that the Chinese later used the same name for Ayutthaya and that the Guangzhou gazetteer of 1297–1307 describes Xiān as controlling Shang-shui Su-gu-di, in which Su-gu-di is identified with Sukhothai. Vickery instead held that the Chinese term referred to the lower Chao Phraya basin as a whole, while Yoneo Ishii concluded that it could denote a group of port-polities around the Bay of Thailand, including Ayodhya and Suphanburi and possibly Ligor. The evidence therefore does not require Xiān to have denoted a single centralized kingdom throughout the period.

The present island was shaped by a river system different from the modern one. The Lopburi River was formerly the main large stream, following a long meander around the settlement, while the Pa Sak and Chao Phraya lay farther away. Settlement occupied riverside levees and other slightly raised ground and was regularly exposed to flooding.

Archaeological evidence indicates a substantial settlement before 1351. Excavations beneath Wat Mahathat and nearby Wat Khun Mueang Chai have found structures predating the 1100s and pottery dating to the 1270s, while Khmer-style stones reused at Wat Mahathat may derive from an earlier structure.

In its early maritime phase, Ayutthaya's rulers were primarily leaders of a port city. Ma Huan described the 15th-century ruler of Ayutthaya as wearing gold-trimmed pants and riding an elephant through the city with one attendant, while living in a modest residence. Ayutthaya's relationship with other cities was initially one of first among equals, requiring its rulers to balance their interests with those of their city vassals. As Ayutthaya incorporated the Northern Cities and adapted their governmental functions during the 15th and 16th centuries, its rulers became more regal and asserted greater authority over their vassals. By the 17th century, increasing wealth from trade enabled the kings to display their power through Angkorian and Brahmic rituals and symbolism.

From the 17th century onwards, Ayutthaya's kings were absolute monarchs with a semi-religious status. Their authority drew on both Hindu and Buddhist ideologies and the concept of natural kingship. At Sukhothai, Inscription 1 portrayed King Ramkhamhaeng as a paternal ruler who heard petitions from subjects who rang a bell at the palace gate.

At Ayutthaya, however, this paternal conception of kingship gave way to the ideal of the chakkraphat (Sanskrit chakravartin), a universal ruler whose adherence to the law caused the world to revolve around him. In Hindu tradition, the king was regarded as an avatar of Vishnu, the destroyer of demons and defender of the people. In Buddhist thought, he was a righteous ruler (dharmaraja) who followed the teachings of Gautama Buddha and sought the well-being of his people.

The kings' official names reflected both Hindu and Buddhist traditions. They were regarded as incarnations of Hindu deities such as Indra, Shiva, and Vishnu (Rama). The coronation ceremony was directed by brahmins, with Shiva regarded as the Hindu god and "lord of the universe". According to the codes, however, the king's ultimate duty was to protect the people and destroy evil.

In Buddhism, the king was also regarded as a bodhisattva, with temple and Buddha-image construction among his important duties as symbols of prosperity and peace. For local subjects, kingship also carried the conception of the "Lord of the Land" or "He who Rules the Earth" (Phra Chao Phaendin). Court etiquette required the use of Rachasap (Rājāśabda, "royal language") when communicating with or about royalty. Under the sakna or sakdina system, codified by King Borommatrailokkanat (1448–1488), the king was said to grant control over land to subjects ranging from nobles to commoners. The system was similar to, but distinct from, feudalism, under which the monarch did not own the land.

Although there is no concrete evidence that this land-management system constituted a formal palace economy, the French François-Timoléon de Choisy, who visited Ayutthaya in 1685, wrote that "the king has absolute power" and was regarded as a god by the Siamese. The Dutch writer Jan van Vliet similarly remarked in the 17th century that the king of Siam was "honoured and worshipped by his subjects second to god." The king issued laws and orders and sometimes served as the highest judge, deciding cases involving major criminals such as traitors and rebels.

In addition to the sakdina system, one of Borommatrailokkanat's institutional innovations was the adoption of the uparaja, translated as "viceroy" or "prince" and usually held by the king's senior son or full brother. The position was intended to regularise succession in a polygamous dynasty, but in practice it created inherent tensions between the king and uparaja and frequent succession disputes.

The power of the Ayutthaya throne nevertheless had limits. Royal authority depended heavily on the king's personal prestige, age, and network of supporters, and the absence of sufficient support could lead to violent coups. Generals, particularly the Kalahom, the minister of the military, were among the most powerful figures in the capital. During the last century of Ayutthaya, conflicts among princes and generals over the throne repeatedly destabilised the court.

With the exception of Naresuan's succession by Ekathotsarot in 1605, "the method of royal succession at Ayutthaya throughout the seventeenth century was battle." Although European visitors sought to identify rules governing Siamese succession, noting that the dead king's younger brother often succeeded him, this custom was not formally enshrined. The reigning king often designated a preferred successor as uparaja, but succession was effectively an "elimination process": any male member of the royal clan, usually the late king's brothers and sons, could claim the throne and prevail by defeating his rivals. Noble factions, foreign merchants, and foreign mercenaries also rallied behind preferred candidates in expectation of benefiting from the outcome.

Ayutthaya followed the mandala system, commonly used by Southeast Asian kingdoms before the 19th century. In the 17th century, its monarchs frequently appointed non-natives as governors of controlled towns and cities to limit competition from the nobility. By the late Ayutthaya period, the capital exerted strong influence over polities in the lower Chao Phraya plain, but its control weakened with distance from Ayutthaya. Thai historian Sunait Chutintaranond notes that "the view that Ayudhya was a strong centralized state" did not hold and that "in Ayudhya the hegemony of provincial governors was never successfully eliminated."

The reforms of King Borommatrailokkanat (r. 1448–1488) placed the king of Ayutthaya at the centre of a highly stratified social and political hierarchy extending throughout the realm. Although evidence is limited, the basic unit of social organization is thought to have been the village community, composed of extended family households. Title to land resided with the headman, who held it on behalf of the community, while peasant proprietors retained its use as long as they cultivated it. Local lords gradually became courtiers (อำมาตย์) or tributary rulers of minor cities. The king came to be regarded as the earthly incarnation of Shiva or Vishnu and as the sacred focus of politico-religious cult practices conducted by royal court Brahmans within the Buddhist court establishment. In the Buddhist context, the devaraja (divine king) was regarded as a bodhisattva. Belief in divine kingship persisted into the 18th century, although its religious significance had by then diminished.

With ample land available for cultivation, the realm depended on securing sufficient manpower for agriculture and defense. Ayutthaya's expansion involved constant warfare, and because no regional power possessed a decisive technological advantage, battles were usually determined by army size. Victorious campaigns brought conquered people into Ayutthaya, where they were assimilated into the labour force. Ramathibodi II (r. 1491–1529) established a corvée system requiring every freeman to register as a phrai (servant) under a local lord, chao nai (เจ้านาย). A clause of the Law on the Institution of Litigation shows freemen already registered under a mun nai in 1356. In wartime, male phrai could be conscripted. Above the phrai was a nai (นาย), who was responsible for military service and corvée labour on public works and the land of his assigned official. Phrai Suay (ไพร่ส่วย) instead fulfilled their obligations through taxation. A phrai could also sell himself as a that (ทาส, "slave") to another lord, who compensated the former nai for the loss of corvée labour. Phrai constituted as much as one-third of the manpower supply into the 19th century.

Wealth, status, and political influence were closely interrelated. Under the sakdina system, the king allotted rice fields to court officials, provincial governors, and military commanders in return for their services. Thai social scientists such as Jit Phumisak and Kukrit Pramoj have extensively examined the system. An official's allotment was determined by the number of commoners or phrai he could command, which in turn determined his status and wealth within the hierarchy. At its apex stood the king, symbolically the realm's largest landholder and, in theory, commander of the most phrai. These phrai luang ("royal servants") paid taxes, served in the royal army, and worked crown lands.

Military recruitment, however, depended on nai or mun nai, literally "lord", officials who commanded their own phrai som ("subjects"). These officials were required to answer the king's call in wartime, making them key figures in kingdom politics. At least two officials staged coups and seized the throne, while conflicts between kings and officials, followed by purges of court officials, were recurrent.

Borommatrailokkanat fixed those allotments by law in 1454, in the Law of the Civil Hierarchy and the Law of Military and Provincial Hierarchies. The scale ran from five sakdina for a slave and twenty-five for a freeman to ten thousand for a chief minister. The structure they set remained in place until officials began receiving salaries in the 19th century.

Outside this system to some extent were the sangha, the Buddhist monastic community, which all classes of men could join, and the overseas Chinese. The Chinese were not obliged to register for corvée and could move about the kingdom and trade at will. By the 16th century the Chinese controlled Ayutthaya's internal trade and held important places in civil and military service.

Uthong was responsible for the compilation of a Dharmaśāstra, a legal code based on Hindu sources and traditional Thai custom. The Dharmaśāstra remained a tool of Thai law until late in the 19th century. A bureaucracy based on a hierarchy of ranked and titled officials was introduced, and society was organized in a related manner. However, the caste system was not adopted.

Determined to prevent another treason like his father's, Naresuan set about unifying the country's administration directly under the royal court at Ayutthaya. He ended the practice of nominating royal princes to govern Ayutthaya's provinces, assigning instead court officials who were expected to execute policies handed down by the king. Thereafter royal princes were confined to the capital. Their power struggles continued, but at court under the king's watchful eye.

To ensure his control over the new class of governors, Naresuan decreed that all freemen subject to phrai service had become phrai luang, bound directly to the king, who distributed the use of their services to his officials. This measure gave the king a theoretical monopoly on all manpower, and the idea developed that since the king owned the services of all the people, he also possessed all the land. Ministerial offices and governorships – and the sakdina that went with them – were usually inherited positions dominated by a few families often connected to the king by marriage. Indeed, marriage was frequently used by Thai kings to cement alliances between themselves and powerful families, a custom prevailing through the 19th century. As a result of this policy, the king's wives usually numbered in the dozens.

Even with Naresuan's reforms the royal government remained uneven. Royal power outside the crown lands was absolute in theory and limited in practice by a lax civil administration. It did not reach far beyond the capital, as the desertion of the provinces in the war of the late 18th century showed.

Ayutthaya's military was the origin of the Royal Thai Army. The army was organized into a small standing army of a few thousand, which defended the capital and the palace, and a much larger conscript-based wartime army. Conscription was based on the phrai system (including phrai luang and phrai som), which required local chiefs to supply their predetermined quota of men from their jurisdiction on the basis of population in times of war. This basic system of military organization was largely unchanged down to the early Rattanakosin period.

The main weaponry of the infantry largely consisted of swords, spears and bow and arrows. The infantry units were supported by cavalry and elephantry corps.

According to a French source, Ayutthaya in the 18th century included these principal cities: Martaban, Ligor or Nakhon Sri Thammarat, Tenasserim, Junk Ceylon or Phuket Island, Singora or Songkhla. Her tributaries were Patani, Pahang, Perak, Kedah and Malacca.

Particularly in the South, Ayutthaya's claims were often discredited or underplayed by the Malay sultanates, resulting in a number of military expeditions starting in the 17th and 18th centuries to subjugate querulous sultanates. These included King Narai's military expedition to the Sultanate of Singora in 1680.

Throughout its existence the kingdom was run by a service nobility of a few thousand, with the rest of the population serfs (phrai), a structure comparable to the contemporary Ancien Regime in France or Feudalism elsewhere in Europe. The social ladder existed during times of war and, particularly during the late Ayutthaya period, of rich commoners challenging the societal status quo of the Ayutthaya Kingdom as a result of commercial prosperity during the kingdom's last 150 years of peaceful existence.

According to the historian Baker, the Ayutthaya peasantry practiced commuter agriculturalism and largely lived in dense areas along the canals leading up to the city of Ayutthaya and other cities within the kingdom, producing homemade goods and textiles for the international market.

What is now known as the Siamese (Thai) language was initially spoken only by the Ayutthaya elite, while everyday people throughout the Chao Phraya delta spoke a medley of Mon, Khmer, and Tai dialects. The Portuguese Tomé Pires described in the early 16th century that "The people [of Siam], and almost the language, are like those of [Mon] Pegu," which may suggest that many or most common people still did not identify with the Tai-language culture of the elites as late as 1515. By the Late Ayutthaya period (1688–1767), the Siamese language and culture had gradually grown to transcend social classes and had been adopted by many of the local people throughout the kingdom.

The Khmer language was an early prestige language of the Ayutthaya court, until it was supplanted by the Siamese language. However it was still continually spoken by the ethnic Khmer community living in Ayutthaya. Many variants of Chinese were spoken in the Ayutthaya Kingdom, with the Chinese becoming a large minority in the kingdom during the Late Ayutthaya period.

Various minor minority languages spoken in the Ayutthaya Kingdom included Malay, Persian, Japanese, Cham, Dutch, and Portuguese.

Ayutthaya's main religion was Theravada Buddhism. However, many of the elements of the political and social system were incorporated from Hindu scriptures and were conducted by Brahmin priests. Many areas of the kingdom also practiced Mahayana Buddhism, Islam and Christianity, influenced by French Missionaries who arrived through China in the 17th century. Some small areas converted to Roman Catholicism. The influence of Mahayana and Tantric practices also entered Theravada Buddhism, producing a tradition called Boran Kammatthana.

The natural world was also home to a number of spirits which are part of the Satsana Phi. Phi (ผี) are spirits of buildings or territories, natural places, or phenomena; they are also ancestral spirits that protect people, or can also include malevolent spirits. The phi which are guardian deities of places, or towns are celebrated at festivals with communal gatherings and offerings of food. The spirits run throughout Thai folklore.

Phi were believed to influence natural phenomena including human illness and thus the baci became an important part of people identity and religious health over the millennia. Spirit houses were an important folk custom which were used to ensure balance with the natural and supernatural world. Astrology was also a vital part to understanding the natural and spiritual worlds and became an important cultural means to enforce social taboos and customs.

The myth and epic stories of Ramakien provide the Siamese with a rich source of dramatic materials. The royal court of Ayutthaya developed classical dramatic forms of expression called khon (โขน) and lakhon (ละคร). Ramakien played a role in shaping these dramatic arts. During the Ayutthaya period, khon, or a dramatized version of Ramakien, was classified as lakhon nai or a theatrical performance reserved only for aristocratic audience. The Siamese drama and classical dance later spread throughout mainland Southeast Asia and influenced the development of high-culture art in most countries, including Burma, and Laos.

Historical evidence shows that the Thai art of stage plays must have already been highly evolved by the 17th century. Louis XIV, the Sun King of France, had a formal diplomatic relation with Ayutthaya's King Narai. In 1687, France sent the diplomat Simon de la Loubère to record all that he saw in the Siamese Kingdom. In his famous account Du Royaume de Siam, La Loubère carefully observed the classic 17th century theatre of Siam, including an epic battle scene from a khon performance, and recorded what he saw in great detail:

The Siamese have three sorts of Stage Plays: That which they call Cone [khôn] is a figure dance, to the sound of the violin and some other instruments. The dancers are masked and armed, and represent rather a combat than a dance. And though every one runs into high motions, and extravagant postures, they cease not continually to intermix some word. Most of their masks are hideous, and represent either monstrous Beasts, or kinds of Devils. The Show which they call Lacone is a poem intermix with Epic and Dramatic, which lasts three days, from eight in the morning till seven at night. They are histories in verse, serious, and sung by several actors always present, and which do only sing reciprocally … The Rabam is a double dance of men and women, which is not martial, but gallant … they can perform it without much tying themselves, because their way of dancing is a simple march round, very slow, and without any high motion; but with a great many slow contortions of the body and arms.

Of the attire of Siamese Khôn dancers, La Loubère recorded that, "[T]hose that dance in Rabam, and Cone, have gilded paper-bonnets, high and pointed, like the Mandarins caps of ceremony, but which hang down at the sides below their ears, which are adorned with counterfeit stones, and with two pendants of gilded wood."

La Loubère also observed the existence of muay Thai and muay Laos, noting that they looked similar (i.e., using both fists and elbows to fight) but the hand-wrapping techniques were different. Muay Thai from the Ayutthaya period (better known as Muay Boran) would greatly influence the modern sport of Muay Thai.

The accomplishment and influence of Thai art and culture, developed during the Ayutthaya period, on the neighboring countries was evident in the observation of James Low, a British scholar on Southeast Asia, during the early Rattanakosin era: "The Siamese have attained to a considerable degree of perfection in dramatic exhibitions – and are in this respect envied by their neighbours the Burmans, and Laos who all employ Siamese actors when they can be got."

Krabi-krabong is a form of sword fighting developed in Ayutthaya that is now recognized as an essential element of traditional Thai culture and arts. Wat Phutthaisawan, a major ancient temple in Ayutthaya, is considered to be the birthplace of krabi-krabong.

The Royal Barge Procession of Ayutthaya Scroll was made in 1797 by Chao Phraya Phra Khlang (Nhon) (1782–1805). The royal tradition of traveling in the Royal Barge Procession dates back to the Ayutthaya era. It has continued and been maintained to later eras until the present king's reign. The epic poem "Lilit Phayuhayatra Phetphuang" describes a detailed depiction of royal processions during the Ayutthaya era. It was composed by Chao Phraya Phra Khlang (Nhon) in 1797 under the royal command of King Phutthayotfa Chulalok Maharaj (1737–1809). It is based on memories of events witnessed during the late Ayutthaya period. The descriptions of the royal barges in "Lilit Phayuhayatra Phetphuang" are similar to those mentioned in accounts from the inhabitants of Ayutthaya.

This scroll depicts the royal funeral procession of King Phetracha. The king died on 5 February 1703 and he was cremated nearly 22 months later on 26 December 1704. This is a typical two-dimensional Thai artwork with black ink and fine lines. It features mythical creatures of Buddhism and the royal urn. The large, ornate wheeled carts (Ratcharot (ราชรถ) are pulled by state officials in Siamese court uniforms. Some officials wear a lomphok. On the utmost left side is a large cremation building for the king called Phra Merumat (พระเมรุมาศ). On the sidelines (top and bottom) are various stalls. Many acrobats perform tricks to entertain the spectators and mourners.

This scroll was purchased in 1716 by Augustus II the Strong (1670–1733), King of Poland. Augustus II received two drawings from Egidius van den Bempden (1667–1737). Bempden was the mayor of Amsterdam and also director of the Dutch East India Company. The container with Bempden's drawings was rediscovered by a curator 300 years later. These drawings are among the few well-preserved Siamese documents of that era.

Ayutthaya was a kingdom rich in literary production. Even after the sack of Ayutthaya in 1767, many literary masterpieces in the Thai language survived. However, Ayutthayan literature (as well as Thai literature before the modern era) was dominated by verse composition (i.e., poetry), whereas prose works were reserved to legal matters, records of state affairs and historical chronicles. Thus, there are many works in the nature of epic poetry in the Thai language. The Thai poetical tradition was originally based on indigenous poetical forms such as rai (ร่าย), khlong (โคลง), kap (กาพย์) and klon (กลอน). Some of these poetical forms – notably khlong – have been shared between the speakers of tai languages since ancient time (before the emergence of Siam).

Through Buddhist and Hindu influence, a variety of Chanda prosodic meters were received via Ceylon. Since the Thai language is mono-syllabic, a huge number of loan words from Sanskrit and Pali are needed to compose these classical Sanskrit meters. According to B. J. Terwiel, this process occurred with an accelerated pace during the reign of King Borommatrailokkanat (1448–1488) who reformed Siam's model of governance by turning the Siamese polity into an empire under the mandala feudal system. The new system demanded a new imperial language for the noble class. This influence set Thai apart from the other tai languages. It brought in Sanskrit and Pali vocabulary in quantity, and required a writing system that preserved Sanskrit orthography for literary use. By the 15th century, the Thai language had evolved into a distinctive medium along with a nascent literary identity of a new nation. It allowed Siamese poets to compose in different poetical styles and mood, from playful and humorous rimed verses, to romantic and elegant klong and to polished and imperious chan prosodies modified from classical Sanskrit meters. Thai poets experimented with these different prosodic forms, producing innovative "hybrid" poems such as Lilit (ลิลิต, an interleave of khlong and kap or rai verses) or Kap hor Klong (กาพย์ห่อโคลง – khlong poems enveloped by kap verses). The Thai thus developed a keen mind and a keen ear for poetry. To maximize this new literary medium, however, an intensive classical education in Pali was required. This made poetry an exclusive occupation of the noble classes. However, B.J. Terwiel notes, citing a 17th-century text book Jindamanee, that scribes and common Siamese men, too, were encouraged to learn basic Pali and Sanskrit for career advancement.

Most countries in Southeast Asia share an Indianised culture. Traditionally, therefore, Thai literature was heavily influenced by the Indian culture and Buddhist–Hindu ideology since the time it first appeared in the 13th century. Thailand's national epic is a version of the story of Rama-Pandita, as recounted by Gotama Buddha in the Dasharatha Jataka called the Ramakien, translated from Pali and rearranged into Siamese verses. The importance of the Ramayana epic in Thailand is due to the Thai's adoption of the Hindu religio-political ideology of kingship, as embodied by Rama. The Siamese capital, Ayutthaya, was named after the holy city of Ayodhya, the city of Rama.

The Thais never lacked a rich food supply. Peasants planted rice for their own consumption and to pay taxes. Whatever remained was used to support religious institutions. From the 13th to the 15th centuries, however, a transformation took place in Thai rice cultivation. In the highlands, where rainfall had to be supplemented by a system of irrigation to control water levels in flooded paddies, the Thais sowed the glutinous rice that is still the staple in the geographical regions of the north and northeast. But in the floodplain of the Chao Phraya, farmers turned to a different variety of rice – the so-called floating rice, a slender, non-glutinous grain introduced from Bengal – that would grow fast enough to keep pace with the rise of the water level in the lowland fields.

The new strain grew easily and abundantly, producing a surplus that could be sold cheaply abroad. Ayutthaya, at the southern extremity of the floodplain, thus became the hub of economic activity. Under royal patronage, corvée labour dug canals on which rice was brought from the fields to the king's ships for export to China. In the process, the Chao Phraya delta – mud flats between the sea and firm land hitherto considered unsuitable for habitation – was reclaimed and cultivated. Traditionally the king had a duty to perform a religious ceremony to bless the rice planting.

Although rice was abundant in Ayutthaya, rice exports were banned from time to time when famine occurred because of natural calamity or war. Rice was usually bartered for luxury goods and armaments from Westerners, but rice cultivation was mainly for the domestic market and rice export was evidently unreliable.

Ayutthaya officially used cowrie shells, prakab (baked clay coins), and pod duang as currencies. Pod duang became the standard medium of exchange from the early 13th century to the reign of King Chulalongkorn. Foreign trade was run by two departments of the crown, the Krom Tha Sai (กรมท่าซ้าย) and the Krom Tha Khwa (กรมท่าขวา). Reported duty rates differ from one observer to another rather than forming a series. Tomé Pires gives an export duty of about 6.7 per cent in the early 1500s, with Chinese importers paying about 16.7 per cent against 22.2 per cent for others; Peter Floris puts the rate at about 5 per cent each way a century later; and a late compilation gives 3 per cent for friendly states and 5 per cent for the rest, together with a tonnage duty of 6 or 10 baht per metre levied on vessels of at least 8 m in the beam.

The late 17th-century Phanna phumisathan records 61 markets inside the walls, 40 of them open daily and 21 part-time, with four floating markets and about thirty street markets outside, and some twenty thousand rafts moored along the moats and waterways as houses and shops. Carts brought hides, horn and forest produce from Khorat and from Battambang to temporary market huts. Suthipob Chantrapakajee argues that the traffic ran both ways: deer and ray hide went to Japan and armour and sword-hilts came back, ivory and horn went to China and medicines containing them returned, and patterns were sent to India for textiles and to China for bencharong ware made to Siamese design. Copper ingots have been recovered from three wrecks in the gulf, at Rang Kwian, Bang Krachai and Ko Si Chang, each with a datable ceramic cargo; he notes that no evidence shows Ayutthaya smelting copper or iron ingots from domestic ore for export, and that Dutch and Japanese lists treat both as imports.

Trade with Europeans was lively in the 17th century. In fact European merchants traded their goods, mainly modern arms such as rifles and cannons, for local products from the inland jungle, such as sappan, woods, deerskin, and rice. Tomé Pires, a Portuguese voyager, mentioned in the 16th century that Ayutthaya, or Odia, was "rich in good merchandise". Most of the foreign merchants coming to Ayutthaya were European and Chinese, and were taxed by the authorities. The kingdom had an abundance of rice, salt, dried fish, arrack, and vegetables.

Trade with foreigners, mainly the Dutch, reached its peak in the 17th century. Ayutthaya became a main destination for merchants from China and Japan. It was apparent that foreigners began taking part in the kingdom's politics. Ayutthaya's kings employed foreign mercenaries who sometimes joined the wars with the kingdom's enemies. However, after the purge of the French in the late 17th century, the major traders with Ayutthaya were the Chinese. The Dutch from the Dutch East Indies Company (Vereenigde Oost-Indische Compagnie or VOC), were still active. Ayutthaya's economy declined rapidly in the 18th century, until the Burmese invasion caused the total collapse of Ayutthaya's economy in 1767.

In 1511, immediately after having conquered Malacca, the Portuguese sent a diplomatic mission headed by Duarte Fernandes to the court of King Ramathibodi II of Ayutthaya. Having established amicable relations between the Kingdom of Portugal and the Kingdom of Siam, they returned with a Siamese envoy who carried gifts and letters to the King of Portugal. The Portuguese were the first Europeans to visit the country. Portuguese mercenaries would also play a major role in the invasion of Lanna in 1539 by King Chairachathirat, and Portuguese soldiers would be considered a respected fighting force for the Kingdom across its existence. Five years after that initial contact, Ayutthaya and Portugal concluded a treaty granting the Portuguese permission to trade in the kingdom. A similar treaty in 1592 gave the Dutch a privileged position in the rice trade.

Foreigners were cordially welcomed at the court of Narai (1657–1688), a ruler with a cosmopolitan outlook who was nonetheless wary of outside influence. Important commercial ties were forged with Japan. Dutch and English trading companies were allowed to establish factories, and Thai diplomatic missions were sent to Paris and The Hague. By maintaining these ties, the Thai court skillfully played off the Dutch against the English and the French, avoiding the excessive influence of a single power.

In 1664, however, the Dutch used force to exact a treaty granting them extraterritorial rights as well as freer access to trade. At the urging of his foreign minister, the Greek adventurer Constantine Phaulkon, Narai turned to France for assistance. French engineers constructed fortifications for the Thais and built a new palace at Lopburi for Narai. In addition, French missionaries engaged in education and medicine and brought the first printing press into the country. Louis XIV's personal interest was aroused by reports from missionaries suggesting that Narai might be converted to Christianity.

The French presence encouraged by Phaulkon, however, stirred the resentment and suspicions of the Thai nobles and Buddhist clergy. When word spread that Narai was dying, a general, Phetracha (reigned 1688–1693) staged a coup d'état, the 1688 Siamese revolution, seized the throne, killed the designated heir, a Christian, and had Phaulkon put to death along with a number of missionaries. He then expelled the remaining foreigners. Some studies said that Ayutthaya began a period of alienation from European traders, while welcoming more Chinese merchants. But other recent studies argue that, due to wars and conflicts in Europe in the mid-18th century, European merchants reduced their activities in the East. However, it was apparent that the Dutch East Indies Company or VOC was still doing business in Ayutthaya despite political difficulties.

Between 1405 and 1433, the Chinese Ming sponsored seven naval expeditions. Emperor Yongle aimed to establish a Chinese presence, assert imperial control over trade, and impress foreign peoples in the Indian Ocean basin, and may also have sought to extend the tributary system. The fleet under Admiral Zheng He is believed to have travelled up the Chao Phraya River to Ayutthaya on three occasions.

Meanwhile, a Japanese colony was established in Ayutthaya and became active in trade, particularly exporting deer hides and saphan wood to Japan in exchange for Japanese silver and handicrafts such as swords, lacquerware, and high-quality paper. Japan also imported Chinese silks, deerskin, and ray or shark skins from Ayutthaya, the latter used to make shagreen for sword handles and scabbards.

The Japanese quarters of Ayutthaya housed about 1,500 Japanese inhabitants, with some estimates reaching 7,000. Known in Thai as Ban Yipun, the community was headed by a Japanese chief appointed by Thai authorities. It comprised traders, Christian converts (Kirishitan) fleeing the persecutions of Toyotomi Hideyoshi and Tokugawa Ieyasu, and unemployed former samurai who had fought for the losing side at the battle of Sekigahara.

Padre António Francisco Cardim reported administering the sacrament to about 400 Japanese Christians in Ayutthaya in 1627 ("a 400 japoes christaos"). Japanese communities also existed in Ligor and Patani.

François-Timoléon de Choisy

Claude de Forbin, French admiral

Louis Laneau, apostolic vicar of Siam

Yamada Nagamasa, Japanese adventurer who became the ruler of the Nakhon Si Thammarat

Constantine Phaulkon, Greek adventurer and first councillor of King Narai

Father Guy Tachard, French Jesuit writer and Siamese ambassador to France (1688)

Jeremias van Vliet, Dutch Opperhoofd

George White, English merchant