History of Isan

Early history

The region's Early Historic period has been put at about 500 to 800 AD, following a pre-literate Iron Age of about 500 BC to 500 AD. The period is usually described in terms of two poles of influence, the ostensibly independent states of Khmer-Hindu Chenla to the south and Mon-Buddhist Dvaravati to the west, terms that have been called increasingly problematic.

The first major civilisation to occupy Isan was considered, by the study of artifacts, to be Dvaravati, whose culture spread into Isan and lowland Laos from the 6th century, with major sites at Mueang Fa Daet in Kalasin Province and Sema in Nakhon Ratchasima Province. The remains of walled and moated towns scattered the region, in the valleys of Chi and Mun Rivers. The enclosures themselves are disputed. Geomorphological work in the upper Mun valley reads some of these features as remnants of old river channels rather than as dug ditches, which weakens the case for a defensive purpose. The remains often show the Buddhist and Hinduist influence, perhaps expanding from the western part or the coastal and the Chao Phraya River basin. In the Phimai region the material culture changed at about the time the first written records appear, on one reading of the excavated sequence. The local Phimai pottery tradition gives way to a grog-tempered, more highly fired and often wheel-turned ware, and incising replaces streak burnishing. Inhumation burial disappears, while urn burials continue and may hold cremated remains rather than bones. The phase that follows, and that precedes the Khmer period, is named the Muang Sema phase, about 600 to 1000. Treating that span of four centuries as one unit is held to be inadequate for the period in which statehood took shape. A finer chronology is called for before the shift from moated settlements to the walled cities of the Khmer state can be followed.

To obtain a fuller and more correct picture of the society and culture of the early urban life on the Khorat Plateau, we must, as Professors Thiva and Srisakra have argued, undertake considerably more archaeological research than has been done thus far. And, I would add, we can further increase our understanding of these societies through systematic research on a number of the indigenous legends of the Thai-Lao people of northeastern Thailand.

— Charles F. Keyes, 1974

Settlement and religious landscape of the Khorat Plateau

The Khorat Plateau and the middle Mekong, east of the core Dvāravatī centres, appear to have developed outside the Dvāravatī political network as a loose landscape of small fortified and moated settlements. Against the site inventories of Thiva Supajanya and Srisakra Vallibhotama, local traditions have been read as preserving the names of early settlements there, especially the legend of Phadaeng Nang Ai and the Tamnan Fa Daet Song Yang (ตำนานฟ้าแดดสงยาง). Mueang Fa Daet, the first site in northeastern Thailand identified as "Dvāravatī" by H. G. Quaritch Wales, is traditionally attributed to the foundation of Chao Fa Ra-ngum in 621 CE. The same reading cautions against applying "Dvāravatī", "Mon" or even "Buddhist" uncritically to the plateau, whose traditions instead depict largely autonomous muang, some with subordinate settlements and others independent, alongside Buddhist practice, fertility cults and local spirit beliefs influenced by Hindu deities. Any cultural or political distinction between Mon and Khmer in the Northeast has been treated as probably not justified until at least 1000 AD. The settlement evidence has been read to the same effect. The largest early historic sites of the plateau are taken for ceremonial rather than administrative centres, with the societies around them integrated more by shared belief and ritual than by political unification. The data are described as far from adequate to test any of the historical models. Literal readings of the documentary record for the pre-Angkorian kingdoms have largely been abandoned. The alternative models that replaced them are held to outrun what the archaeology can yet test.

The Dvāravatī label on the plateau rests partly on evidence since re-examined. Quaritch Wales dug the first early historic sites there, at Muang Phet and Ban Thamen Chai. He read their planning and pottery as close connections with central Thailand. Pottery from fill in the Phimai temple compound was compared with late Dvāravatī ware from Chansen. Excavated wares from Mueang Fa Daet Song Yang and Ban Krabuang Nok were connected closely with central Thai Dvāravatī sites.

Later work has cast doubt on those connections. Against larger collections from mainland Southeast Asia the relationship appears less close than once supposed. The pottery of sites near Phimai seems only distantly related to central Thai Dvāravatī ware. New survey and excavation at Muang Phet found what had been taken for Dvāravatī pottery to be the ordinary late prehistoric pottery of the region. Similarities in manufacturing technique and the use of grog temper remain. The epigraphy runs the other way. Sanskrit was the language most used on the plateau, as in Cambodia, while Pali was commoner in the Chao Phraya basin. Neither the Phimai region nor the Lam Pao excavations, however, suggested close connections with the Cambodian evidence then known.

The region's sema stones, Buddhist boundary markers, likewise show a local tradition. Narrative carvings from Mueang Fa Daet Song Yang and Ban Nong Chat depict jātaka scenes and the life of the Buddha, and mark consecrated ground for ordination and other rites. They are generally dated to the 7th–11th centuries and classified as Dvāravatī work. The Mon sīmā stones of the northeast, although they illustrate Jātaka scenes, are noted to carry no glosses identifying the scenes and are inscribed instead with matter relating to the donor. Their use has been argued to have arisen locally as a response to the Vinaya requirement for boundary markers, whose form it leaves unspecified. Excavated examples occur not only around ordination halls but also stupas, Buddha images and prehistoric rock shelters, with eight to twenty-four stones in some settings. Vimoltip Singtuen and colleagues give four to sixteen for directional settings. The later standard of eight stones is first prescribed in the Kalyāṇī inscription of 1477–78, contrasting with this earlier variety. An earlier theory held that the tradition reached the Kalyāṇī sīmā at Thaton in lower Myanmar through Mon fleeing Angkorian expansion in northeast Thailand. More recent comparison, however, finds substantial differences in form, composition and style between the two corpora and suggests that the lower Myanmar tradition developed independently.

Political developments in the Plateau

Inscriptions and religious remains

Epigraphic and Chinese evidence likewise points to the plateau being divided among many small polities between the 6th and 9th centuries, with several inscriptions naming local rulers or nobles as religious donors. The Sanskrit Phimai Inscription No. 1 (K.1000) names the Buddhist ruler Sauryavarman in the Phimai region; the Hĭn K‘ôn inscriptions (K.388 and K.389) name the Buddhist noble Nrpendradhiphativarman and his similarly named father; and the Don Mueang Toei inscription records King Pravarasena of Sankhapura. The Hĭn K‘ôn inscriptions have been read as recording the erection of four sema stones. They also record a Buddhist temple and monastery, endowed with ten pairs of cattle, gold and silver utensils, rice-fields and a plantation of twenty betel nut trees. The Wat Ban Waan inscription names King Srimanya, while the Wat Pa Nong Peng inscription names King Śrīmānarājā and describes his reign as a time of political turmoil. The Don Mueang Toei inscription further gives a genealogy of three kings of Sankhapura, Pravarasena, Kroñcabahu and Dharmasena, and no link has been established between them and the rulers of Cambodia. Together these records attest multiple local polities before Angkorian authority arose to the south. The changes associated with pre-Angkorian Cambodia have been placed in the Mun valley at the same time, among them brick religious architecture, the use of inscriptions, new artistic traditions and the emergence of ruling elites.

Thailand's Old Mon inscriptions have been divided into three phases, with the plateau forming the second, dating to about the 8th to 10th centuries and using a post-Pallava script. Most are short texts on sema stones recording meritorious acts and donors' names. They come from Chaiyaphum, Khon Kaen, Udon Thani, Sakon Nakhon, more recently Phetchabun, and Kalasin, including one dated to 771 CE, with another group known from Vientiane in Laos. Their distribution does not by itself define Dvaravati's extent, since sites bearing such inscriptions need not have been affiliated with it. The unusually large stone images from Wat Chanthuek and Sung Noen have likewise been taken to indicate an independent centre of power and wealth around old Khorat. The language of the inscriptions has been read as pointing in a different direction. Sanskrit was the language most used on the plateau, as in Cambodia, while Pali was more common in the Chao Phraya basin. On that reading the epigraphy points to Cambodia rather than to the west as the source of outside contact.

The reach of these religious traditions into small inland polities is also illustrated by a hoard of silver and gold found in 2008 at Nong Hua Thong in Savannakhet, Laos, at a fortified settlement on the Xe Bang Fai. Dating broadly to the 8th to 10th centuries, it includes silver vessels in late Tang style, a silver Garuda, and a repoussé plaque of a seated ascetic tentatively identified as Kubera. The hoard is held by the provincial government and closed to study.

Chenla and Dvaravati spheres

During roughly the same period, corresponding to the reign of Mahendravarman of Chenla (r. 600–615), parts of the Khorat Plateau may have come under temporary Chenla influence. His victory inscriptions extend across the Mun–Chi basin, from Dong Mueang Aem in present-day Khon Kaen Province to the Phimai region and the mouth of the Mun in Ubon Ratchathani. One inscription (K. 969 / P.Ch. 5), from Prasat Khao Chong Sa Chaeng in Ta Phraya, Sa Kaeo, records the digging of the Śaṅkara Taṭāka, extending the pattern south of the Dângrêk range. Others place Mahendravarman's campaigns along the Mekong as far as Champasak in southern Laos. These inscriptions were long taken as evidence of Chenla administering conquered territory through vassals. Because they record victories without demonstrating lasting control, however, it has been argued that they do not establish direct Chenla authority beyond the Dongrek Mountains. The evidence of any southern control in the northeast at this time has been called far from compelling, and the Khmer kings do not appear again in the region's inscriptions for some centuries. The campaigns are instead regarded there as temporary expeditions with limited political effect, after which regional inscriptions name no ruler from the Tonlé Sap basin for several centuries.

A firmer connection with Chenla may date from the reign of Isanavarman I (r. 616–637), Chinese records placing a polity called Bhīmapura under him which some identify with Vimayapura, Phimai. Others read Chinese accounts of Zhu Jiang and Can Ban as allies of Chenla by marriage to mean that polities of the central plateau and upper Pa Sak basin formed dynastic ties with his court. Much of the plateau appears to have lain where the Chenla and Dvaravati spheres overlapped. Its northeast, covering present-day Nakhon Phanom and Sakon Nakhon and Khammouane in Laos, appears in early 7th-century Chinese sources as the two districts of Changzhou Prefecture (長州 or 裳州). One reading places the early Tai polities of Gǔ Láng Dòng (古郎洞) and Jūn Nà Lú (君那盧) in this region. Changzhou, however, disappears from the Chinese record after the emergence of Wen Dan, whose relationship to it remains unclear.

From the mid-7th century, Chinese sources suggest weakening Chenla influence, with several polities appearing independently. Zhān Bó, often placed at Champasri, sent tribute to China in 657 and may have formed from the merger of Zhān Guo (瞻國) and Bó Guo (博國). Pó Àn (婆岸), recorded in the New Book of Tang, has been tentatively placed around modern Phon District. The same reading takes Zhān Bó, Pó Àn and several states of the Menam valley and Cham coast as a trans-Mekong trade confederation distinct from the Dvaravati polities of the coast. After the reign of Jayavarman I (r. 657–681), Wen Dan may have separated from Chenla between 681 and 707, before sending its first recorded tributary mission to China in 717. Wen Dan has been identified with Mūladeśa, a toponym attested in the K.187 inscription. Chinese records further state that in 755 Wen Dan assisted a native Nghean lord in wars against the Chinese governor at Jiaozhou, after which the lord enthroned himself as Hei-ti (lit. 'Black Emperor'). Wen Dan's influence has likewise been suggested to extend beyond the Khorat Plateau into the Si Thep and northern Tonlé Sap regions, where pre-Angkorian Buddhist and architectural remains have been interpreted as reflecting connections with the Wen Dan cultural sphere.

Java period

References to the plateau grow rarer from the 9th century, with Wen Dan's last recorded mission to China in 799. The plateau and much of present-day Laos are generally held to have entered the "Java Period" as Angkor rose in the Tonlé Sap basin. Since Java also appears in Angkorian foundation narratives, Its referent is debated, whether the island of Java, Cham-related mainland polities, or other maritime powers of the region. A further reading adds the northern Malay Peninsula, a principality far up the Mekong, and Wen Dan itself, while noting that the tradition has also been treated as a late myth. Inscriptions of Jayavarman VII (r. 1181–1218) further complicate the issue by naming a "King of Yavana" alongside a "King of Java" and two kings of Champa, indicating distinct but unidentified entities.

Angkorian period

From the 11th century, the Dvaravati or Mon culture from the Chao Phraya River basin was gradually displaced by the Khmer Empire of Angkor. Many principal centres have conventionally been described as Angkor's tributary states. The Wat Cong Ko inscription (K.1249) of 1008 records a donation by Jayavīravarman to the god Vimāya at Phimai after he had lost Angkor. This has been read as showing him holding authority on the plateau in those years. A number of temples in Khmer style stand in Isan, most notably in the southern part, at Phanom Rung and Phimai, which lie on the so-called Ancient Khmer Highway, the direct link to Angkor. Angkor-style temples have been described at the passes down into the plain and at Si Thep, Mueang Sema and Si Mahosot. The same account describes small wat built in Angkor styles at the centre of old moated settlements on the plateau, and notes their local individuality. They do not say the builders were subordinate. Inscriptions from the region have been read as recording connections between vassal towns and the court of Angkor. The relationship has been read differently, with ties of mutual allegiance between Cambodian kings and the existing elites of the Northeast were perhaps more common than political domination even after 802. On that account this held until the Mahidharapura dynasty, when one Mun valley line became the rulers of Angkor.

Urangkhathat and the middle Mekong network

The middle Mekong and Khorat Plateau formed a transitional zone between the Dvāravatī sphere and the pre-Angkorian polities. Wen Dan last sent an embassy to the Tang court in 799, after which it disappears from the written record. Archaeological evidence indicates that the middle Mekong came increasingly within the Angkorian sphere from about the 9th century, while later local traditions provide much of the surviving evidence for the region's political geography.

The Urangkhathat (ตำนานอุรังคธาตุ), the foundation legend of Phra That Phanom, preserves a network of interconnected polities rather than a unified kingdom. Its political geography has been dated to the 10th century and later, chiefly from the earliest architectural phase of Phra That Phanom, which predates later Lao and Isan renovations. Its principal centres include Sri Kotabun (ศรีโคตรบอง), Nong Han Luang (หนองหานหลวง), identified with Sakon Nakhon, and Nong Han Noi (หนองหานน้อย), or Khun Khom Nakhon (ขุนขอมนคร), in the Kumphawapi area of Udon Thani. The tradition also connects them with Candrapuri (Vientiane), Sri Sattanak (Luang Prabang), Chulani Phromathat, associated with the Cham polity at modern Huế, and Indaprasthanagara, whose location remains disputed.

Within this network, the Urangkhathat gives particular prominence to Saket Nakhon Roi Et Pratu (สาเกตุนครร้อยเอ็ดประตู; lit. 'Saket, city of a hundred-and-one gates'), which it places on a level with Yothika (โยธิกา), Kurunta (กุรุนทะ), or Ayodhya in the Menam Valley. Its ruler, Phaya Suriyawongsa Sitthidet, is described as exercising ritual overlordship over subordinate polities whose rulers presented gold and silver flowers each year. The name Roi Et, meaning a hundred and one, is generally understood as a symbol of pre-eminence rather than a literal number of dependent towns. Saket, an Indian toponym associated with Ayodhya in Hindu, Buddhist and Jain traditions, appears to function as borrowed sacred geography legitimising regional kingship rather than as evidence of direct contact with India.

Nong Han and the Chi–Mun basins

A more localized account of political organization on the northern Khorat Plateau appears in the legend of Phadaeng Nang Ai, centred on the Nong Han–Sakon Nakhon area also named in the Urangkhathat. It portrays a ruler known as Phaya Khom (พญาขอม) as king of Muang Nong Han. This polity has been identified with present-day Nong Han in Udon Thani Province, although the earliest Lao accounts associate the legend with the Sakon Nakhon site. Both sites have rectangular, Angkorian-style moated plans. In these accounts, Phaya Khom placed his sons and grandsons over a network of muang extending across the northern and central Khorat Plateau, including Muang Chiang Hian–Ban Iat (เมืองเชียงเหียน–บ้านเอียด), Muang Si Kaeo–Phak Waen (เมืองสีแก้ว–ผักแว่น), Muang Hong–Muang Thong (เมืองหงส์–เมืองทอง), and Muang Pheng (เมืองแพง). Some versions also include Muang Fa Daet in this network. The story ends with Muang Nong Han sinking beneath the water. This motif has been taken to favour Sakon Nakhon, whose old moated city includes a low-lying northern sector subject to seasonal flooding, while the Urangkhathat similarly places the submersion of Khun Khom Nakhon at Nong Han Noi. Regional rulers in these traditions are also consistently called Phaya Khom, an epithet associated with the Angkorian sphere, and the traditions preserve relationships among the principal muang of the middle Mekong and Khorat Plateau.

The southern basin followed a different course. In the late pre-Angkorian period, the area, where Dvaravati culture spread without a strong central authority, formed part of the loosely organised and generally identified as Canasapura emerged around Mueang Sema in present-day Nakhon Ratchasima. From the 9th century, the region came increasingly within the Angkorian sphere. The earliest of those traces has been put at Indravarman I, who asserted his authority in 877 on a series of inscriptions running from southern Cambodia into Northeast Thailand. Yasovarman I, crowned 889, founded 100 ashramas in Cambodia and Northeast Thailand, one of them at Phanom Rung. Angkorian influence overlaid rather than immediately replaced the existing Dvāravatī landscape, producing a mixed Dvāravatī and Khmer material culture, while inscriptions from Mueang Sema still placed the polity outside "Kambujadesa", Angkor proper. Integration continued through the 10th and 11th centuries, including under Jayavarman V (r. 968–1001), whose court brahmin Yajñavaraha founded religious establishments at Mueang Sema, and Suryavarman I (r. 1002–1050), when Prasat Preah Vihear was built on the Dângrêk escarpment above the region. By contrast with the network of semi-autonomous centres preserved in middle Mekong traditions, the southern Mun basin has been described as progressively incorporated into the Angkorian state. That integration is dated to about 1000, under Suryavarman I. The growth of Phimai to twice the size of any other site in the region, with the straightening of the distribution of site sizes, is read as marking a single site hierarchy. Survey in the Phimai region recorded 76 habitation sites of the Khmer-period Lopburi phase across 700 km² of sample blocks, against 71 of the late prehistoric phase. The Khmer-period sites were smaller on average. The large moated villages of the late prehistoric period gave way to small unenclosed hamlets, which may reflect a single political authority and an end to frequent warfare in the region.

Sukhothai period

The Sukhothai Kingdom is conventionally described as breaking free from the Angkor Empire in the 13th century. Although Isan is not thought to have been a part of the Sukhothai kingdom due to the lack of clear evidence, the Khmer empire became weaker and withdrew towards its Cambodian heartlands, and Isan was divided among fragmented muang (เมือง) city-states or statelets. However, many Khmer-speaking people remained and are still a prominent fixture in the southern area, constituting the majority in present-day southern part of the region such as in present-day Surin Province, Buriram Province and are also numerous in part of Sisaket Province.

Pre-Lan Xang political networks in the Korat Plateau

With the Dvaravati and Angkorian networks in decline, the Khorat Plateau became a frontier in the late 13th and early 14th centuries where three spheres overlapped. These were the declining authority of Angkor over its Mahidharapura- and Sakon Nakhon-linked networks, the expanding Siamese kingdoms of Sukhothai and later Ayutthaya, and the Lao mueang of the middle Mekong, united by Fa Ngum as Lan Xang in 1353. Direct epigraphic and archaeological evidence is thin, so the political geography is reconstructed largely from later chronicles, retrospective place names, and comparison with Angkorian and early Lao sources, leaving many identifications provisional.

A long-standing debate concerns the location of Mueang Rad, the polity ruled by Pho Khun Pha Mueang (fl. late 12th – mid 13th-c.) in the traditional founding narrative of Sukhothai. It has been identified with the moated site of Mueang Kao (Khorakhapura, also called Nakhon Raj)–Mueang Sema in modern Sung Noen, Nakhon Ratchasima, while Chit Phumisak later supported the identification through toponymic analysis. Other scholars place Mueang Rad in the lower Nan basin near modern Uttaradit or the Pa Sak Valley in Phetchabun, or suggest that Pho Khun Pha Mueang ruled more than one polity. The Khorat hypothesis has also been questioned because the Phimai corridor appears to have remained aligned with Angkor until the early 15th century. Ayutthaya then launched a separate campaign to secure the region before the sack of Angkor Thom in 1431. The Lao chronicle tradition offers another perspective. The Lan Xang Chronicle records Fa Ngum's conquest of Mueang Phrommathat, identified by later scholars as Phimai, followed by campaigns against other centres across the Khorat Plateau. Because these accounts were compiled centuries later and incorporate legendary material, their place identifications remain tentative.

Archaeology gives a different picture. Surveys of early Lan Xang settlement centre on the Loei–Nong Bua Lam Phu–Udon Thani–Nong Khai corridor, where securely dated sites lie west of the Phu Phan Range. They have been interpreted as a frontier network associated with Fa Ngum's reign along the Phetchabun and Phu Phan corridors. This leaves much of the central plateau outside the initial archaeological network, in contrast to chronicle identifications that place several conquered mueang around Phimai. Most inscriptions from the region date only from the later Vientiane period, leaving the two reconstructions unreconciled. The settlement record of the southern plateau shows a comparable break. No deposits have been found with a pottery type that can be placed between the Khmer-period Lopburi phase and the later Thai Khorat phase, and no cultural deposits radiocarbon dated to the intervening centuries. Sites in marginal areas were abandoned, most of them not reoccupied until the early 20th century, when Lao settlement and population pressure brought migrants back to them. The decline has been explained as environmental, through the fuel demands of large-scale iron and salt production. That is called plausible, though no direct evidence of the ecological effects exists, and beside it are set the collapse of a temple-centred economy and the effects of recurrent warfare. Oral tradition is read as agreeing with the archaeology. Villagers in the resettled areas tell of grandparents and great-grandparents moving in, while on the alluvial plain of the Mun no such movement is remembered. Warfare and its effects on health have been offered as a further cause, with abandoned rice fields as breeding ground for malarial mosquitoes. The written records give at least six Thai campaigns against the Khmer between 1350 and 1430, and more later. When Aymonier and Lunet recorded village populations on the plateau at the end of the 19th century, the densities still appear far below those estimated for the late prehistoric and Khmer periods. The southern and southeastern margins of the plateau continued to be inhabited by Kuy communities, whose presence predates the documented Kuy chiefdoms of the 18th century. A proposed Kuy polity centred on Tbong Khmum in the 14th–16th centuries likewise rests mainly on later chronicles and lacks archaeological or epigraphic corroboration. Beyond the plateau, southern Laos and northeastern Cambodia were likewise divided among small riverine polities around Champasak, Salavan, and Attapeu. Later interpretations of Fa Ngum's campaigns place these areas within Lan Xang, but archaeological evidence for the immediately pre-Lan Xang period remains limited.

Lao and Siamese chronicles describe a frontier settlement between Lan Xang and Ayutthaya after Fa Ngum's campaigns, accompanied by a royal marriage alliance between Fa Ngum and an Ayutthayan princess.

Lan Xang

The Lao kingdom of Lan Xang was established in Luang Prabang in the 14th century by Fa Ngum. The kingdom's name means Million Elephants, echoing the name of the neighboring northern kingdom of Lan Na "Million Rice Paddies". As the Khmer Empire continued to retreat under pressure from the neighboring Tai kingdoms of the Ayutthaya Kingdom and Lan Xang. Ayutthaya established a presence at Nakhon Ratchasima and Phimai. However, the bulk of the Khorat Plateau fell into the mandala of Lan Xang. The Siamese side of the division is set out from the same survey. An Ayutthayan army was raised at Khorat in 1593, and Thai control of the town is recorded in 1638. Under Narai, who reigned from 1656 to 1688, Khorat was fortified and became the provincial centre for the parts of the plateau under Thai control. Phimai, Chan Tuk, Chaiyaphum, Buriram and Nang Rong are named as the towns within its circle of power.

Lao settlers began gradually moving across the Mekong into Isan between the 14th and 16th centuries. Major cities were established at Loei, Viang Khuk, Nong Khai, Nong Bua Lamphu (traditionally held by the crown prince), Sakon Nakhon, Nakhon Phanom, Roi Et, Suwannaphume, and Champasak. Additional settlements were located Nong Han Noi, Mahukhanakhon, and a number of settlements across the Mekong from Vientiane including Sri Xiang Mai, Phon Phao, Tha Bo, Say Fong, and Phon Phisai. Many of these early settlements were destroyed or abandoned in the aftermath of the Lao rebellion (1826-1828). Lan Xang was divided by a succession dispute after the death of King Sourigna Vongsa in 1700, into the competing Kingdom of Vientiane, Kingdom of Luang Phrabang and Kingdom of Champasak. Most of what would become the Isan was split between Vientiane and Champasak.

Siam

With the rise of King Taksin, his Thonburi Kingdom began expanding direct control over the region. Thonburi forces invaded and took control of the Kingdom of Luang Phrabang and the Kingdom of Vientiane and Isan entered its direct orbit.

In 1718, Lao settlers in the company of an official in the service of King Nokasad of the Kingdom of Champasak founded mueang Suwannaphum.

During late 18th century, the Lao kingdoms of Luang Phrabang and Champasak were increasingly at odds with Vientiane. As Vientiane struggled to maintain control of Isan, a number of dissidents began migrating from Vientiane and taking refuge in Isan. Most of them recognized Siam as their suzerain according to the mandala system. Under this system, mueang leaders were granted something equivalent to a fiefdom and a noble title as governor, having full right of rulership over their towns. Thus they eventually became the subjects of the royal court in Bangkok. New towns were founded such and Chaiyaphum along with many minor towns such as Han Chai Cham Na.

In 1827, King Anouvong of Vientiane rebelled against Siam. After a successful attack on the stronghold of Korat, he was defeated and in Yasothon a memorial to the defeat was raised. The defeat of Anu's revolt was followed by forced migrations from defeated Lao kingdoms to Isan, further increasing the dominance of Lao culture in the region but weakening the mueang of the Lao. The governors of these new towns were semi-autonomous. They had right to rule, to tax their own subject, part of which might be transferred to Bangkok periodically. If time of war, these local rulers had a duty to send troops to defend Siam.

Following defeat in the Franco-Siamese conflict, Siam ceded Luang Phrabang and Champasak to France in 1893 and 1904. Isan became the kingdom's northeast frontier as the buffer zone between French Indochina and Siam, with Siam becoming a 'buffer zone' between the United Kingdom and France with the Entente Cordiale. Thus began the process of annexation of Isan area into the modern Siamese nation.

Prince Damrong Rajanubhab, appointed Minister of Interior in 1892, introduced the monthon administration system known as Thesaphiban (เทศาภิบาล, literally control over territory). The 1897 Local Administration Act formally adopted it. It transferred much power from the traditional provincial governors drawn from the local nobility to the newly established monthon commissioners and civil servants (รองอำมาตย์, court support) appointed by Bangkok. In 1902, local revolts broke out in Isan, often led by charismatic religious leaders called Phu Me Boon (ผู้มีบุญ) or Phi Bun ผีบุญ (Holy man). One of these rebellions (Prakot Kan Pi Bun ปรากฏการณ์ผีบุญ) recalled the resistance to Thonburi authority by the monk Chao Phra Faang, 1768–70. A former monk and Phu Mi Bun in the Ubon Ratchathani area headed a millenarian sect built on his apocalyptic predictions. The prophecy created panic among almost all of the Isan people until the Bangkok government eventually crushed it.

From the 20th century onwards, Siam gradually consolidated its control over Isan through a programme of Thaification. The introduction of a national school system in the 1920s replaced instruction by monks in the Isan Lao language with teaching in the Thai language only. Radio and television, when they began, also broadcast in Thai. They included (and still do) twice daily broadcasts of the Thai National Anthem.

Even after the Revolution in 1932, when democratic rule began, Isan was ignored by the new Thai government. Most of the region was underdeveloped. Apparently new or necessary infrastructure were hardly built. Albeit the biggest part of Thailand, until now, there are still only two railways in the region and most of modern paved roads were built in the 1960s and 1970s.

Communism

In the latter half of the 20th century, Isan was perceived by the Thai government as a potential breeding ground for Communism. The region's poverty, special history, remoteness and inaccessible terrain all contributed to this fear.

Inevitably, the extent to which Communist insurgents were a real threat in Isan is hard to determine. It is known that there were a number of political attacks from the 1960s onwards, and that Communist activists and equipment entered the region from Laos. On the other hand, the number of guerrillas probably never exceeded a few thousand, and the combination of action by the security forces and the offers of amnesties had largely ended the threat by the early 1980s.

US bases

The fight against Communism persuaded the government to allow the establishment of a number of US bases in Isan, notably in the provinces of Nakhon Ratchasima, Nakhon Phanom, Udon Thani, Nakhon Sawan and Ubon Ratchathani. Although the bases were directed at Communists in Laos, Cambodia and Vietnam, they had an indirect effect in promoting development and opposing Communism in Isan. The bases required the creation of improved transport links, facilitating the integration of Isan with the rest of Thailand. The most important of these was Highway 2 named the Mittraphap Road (Friendship Highway,) which links with Bangkok and Isan. and other northeast highways that being with the numeral 2, which link the region's major cities with each other. These remain Isan's primary road links, with many later to be incorporated into the 21st-century Asian Highway Network. Complemented by Thai government programs to build minor roads, these projects did much to bind rural Isan more closely to the cities and to Bangkok.

The number of US servicemen reached its peak in 1969 at 50,000. This influx of US personnel also had a direct effect in exposing the region to western culture. This helped to promote the development of the region, but it also created a sizable sex industry in the vicinity of the bases. Finally, the US military presence contributed substantial sums of money to the area's economy, with emigrant-spouses who accompanied American servicemen continuing to send substantial sums home. The bases were closed at the end of the Vietnam War in 1975.

Development

The Thai government promoted development in Isan as one weapon in the fight against Communism. In particular, Field Marshal Sarit Dhanarajata, who took control of the country in 1958, was a native of Isan and promoted a number of development projects there.

From the 1960s onwards, the government launched a string of development programmes aimed wholly or in part at Isan. These began with a five-year development plan announced in 1961 and backed by US aid. The program's "top down" approach was satirized in a country song still being sung decades later. An Accelerated Rural Development Programme followed in 1964, again with US support. This was administered by provincial governors in the hope of circumventing the inefficiencies of central government, but it could not evade the problems of bureaucracy, corruption and a conservative mindset which hampered all development efforts.

1960s projects to introduce improved crop strains have been criticised for forcing farmers to take out loans to pay for the seed, fertiliser and equipment required, while reducing genetic diversity. Even in the 1970s, government per capita spending on rural assistance programmes was lower in Isan than anywhere else in Thailand.

Several programmes nevertheless went ahead. Mobile Rural Development Units focusing on health education trained about 1000 field workers a year in the late 1960s. Hydroelectric schemes such as Nam Pong/Ubon Ratana power station in Khon Kaen and Lam Pao in Kalasin supplied electricity. Modern toilets were distributed, and government rice purchase programmes maintained prices.

Education efforts increased the proportion of children attending high school from 4.4% in 1970 to 80% by 2000. Universities were established beginning with Khon Kaen University in 1964, soon followed by Mahasarakham University and Suranaree University of Technology.

Recent history

An important political issue at the end of the 20th century was the construction of the Pak Mun dam in the district of Khong Chiam, in Ubon Ratchathani Province. The project was completed in 1994, flooding 117 square kilometres of land and displacing around 3000 families. The project has been criticised for insufficient compensation payments, adverse effects on the fisheries of the Mun River, and failure to produce the projected power output.

Protesters against the Pak Mun dam joined other grassroots activists in 1995 to form the Assembly of the Poor. The group sought to involve the poor in decision-making and to have their interests taken into account. The group has organised a number of protests against the project in Bangkok. The now deposed prime minister, Thaksin Shinawatra, responded by claiming that activists NGO Living River Siam are trouble-makers who do not reflect the opinions of ordinary people. The same issue arose with the Rasi Salai Dam in Sisaket Province, which was also completed in 1994 for the generation of electricity; it was abandoned for that purpose in 2000 and converted into a recreation area.

Early 21st century