Wen Dan

Wen Dan (文單)
580–944
Political entities in Mainland Southeast Asia in the 7th century.
Capital	Kantharawichai
Religion	Buddhism
Historical era	Post-classical
• Established	580
• Broke away from Chenla	681
• First tribute to China	717
• Allied with Tai–Hmong	722
• Last tribute to China	799
• Disestablished	944
Preceded by Succeeded by Chenla Angkor Kuruntha

Wén Dān (Chinese: 文單; Thai: เหวินตัน), proposed Bhavapura, was a group of ancient Mon political entities that existed around the 6th–10th centuries CE in the interior of mainland Southeast Asia scattered around the central Mekong Valley in the present-day northeast Thailand. It was mentioned in the Chinese annals of the Tang period (618-907 AD) as a dependency on the trans-Mekong trade route from the ancient city of Chiaochih (jiāo zhǐ 交趾; Giao chỉ; near the present-day Vinh of Vietnam) to India. It sent representatives to China in 717, 750, 753, 771, 779, and 799. Wen Dan or Bhavapura is considered the origin of the united Chenla.

Initially, Wen Dan was believed to be Vientiane, but according to the location given in the Chinese annals as well as archaeological evidence, it is supposed to be in the Chi River basin, centered in Kantharawichai, with Mueang Fa Daet Song Yang as outer center and Champasri as the vassal. Several historical evidences supports the connection between Wen Dan and Si Thep in central Thailand. The Chinese text Tang Huiyao mentions Wen Dan as a state located 6 days' travel by land northwest of Keoi Lau Mì.

According to the Dvaravati Buddhist boundary stones (Bai sema) dated the 8th century found on Mt. Kulen, Woodward (2003) proposes that Wen Dan once controlled the Angkor region before Jayavarman II proclaimed the independence of the Kambujadesa from Java in 802. Jayavarman II probably either defeated Wen Dan and then moved the capital from Indrapura to Yaśodharapura to the north, or formed ally with the communities in Mun and Chi watersheds to against Si Thep to the west.

History

Dvaravati–Chenla period: 580 – 944

Federated Chenla: 580 – 681

Main article: Chenla

It was proposed by Pierre Dupont that Chenla was originated in the Mun Valley, and was ruled by the Bhavavarman I, who, together with his successor Mahendravarman I, expanded territory southward to the Bassac-Pakse region, which considered the original land of the Khmer people that later known as Sreshthapura. The expansion campaign continued deep south along the Mekong Basin, and they successfully established the new capital at Sambhupura in 618. The reign of their successor, Isanavarman I, was considered the golden period of the kingdom, as he was able to subdue the maritime trade polity of Funan, which previously was their suzerainty, as well as vassalizing several polities to the northwest in the Tonlé Sap Basin, extending the influence to the Menam Valley in modern central Thailand, where the Dvaravati culture dominant. Following the reign of Isanavarman I, Chenla declined and eventually broke apart in the 8th century. However, this presupposition has recently been questioned as Khmer inscriptions that date pre-7th century are found to be concentrated in present-day central to southern Cambodia and the Mekong delta in southern Vietnam. In contrast, northeastern Thailand has no Khmer inscription dated before the 8th century, as well as the adjacent area of southern Laos and northwest Cambodia, previously stated to be the original homeland of Khmer, were instead dominated by Cham inscriptions. Thus, Bhavavarman I and Mahendravarman I probably originated in the southern plain of the Tonlé Sap and later expanded their influence northward to Bassac-Pakse and the Chi-Mun Valley.

The origin of Bhavavarman I remains disputed; he was potentially a prince of Si Thep's king, Prathivindravarman, as cited in the K.978 Ban Wang Pai Inscription. This assumption is corroborated by numerous archaeological findings in the proposed regions of Wen Dan, encompassing Kantharawichai, Mueang Fa Daet Song Yang, and Champasri, showing a substantial connection to Si Thep in central Thailand.

Independent polity: 681 – 944

Phra Phuttha Ming Muang in Kantarawichai, Mahsarakham

Prataduyaku in Mueang Fa Daet Song Yang, dated the 7th-11th century.

Dvaravati's Sema stone recovered from Mueang Fa Daet, Kalasin

Artifacts and remnants discovered in the suggested area of Wen Dan show the influence of Dvaravati in the area before the onset of the Angkor period in the 10th century

Due to the weak rule at Sambhupura, the upper Chenla broke away in 707, and this new kingdom was named "Bhavapura" in honor of its first great king, Bhavavarman I, as proposed by Pierre Dupont. Meanwhile, George Cœdès gave the date of the separation at the end of Jayavarman I' reign, that is 681. The remaining lower Chenla – Sambhupura, Vyādhapura, and Bālādityapura – later dissolved in the late 8th century. Following the secession, Wen Dan was probably ruled by Bhavavarman I's offshoot. It was believed that Sri Jayasimhavarmman, cited in the Monic K.404 Stèle de Phu Khiao Kao found in Chaiyaphum province, dated 7th–8th century, was the first Wen Dan king. The sole historical documentations concerning Wen Dan during this period are the Chinese records from the Tang Dynasty, which provide more insight into Wen Dan's relations with China than its dealings with the lower Chenla. The travel route to China clearly through the Annamite mountain passes to Nghean, and thereafter to Jiaozhou.

Wen Dan first sent tribute to China in 717. Subsequently, in 722, Wen Dan assisted a native Nghean lord – probably a Tai or a Hmong – in the wars against the Chinese governor at Jiaozhou, which they won, conquering Jiaozhou, and the native lord enthroned himself as Hei-ti (lit. 'Black Emperor'). This royal connection allowed the Tai–Lao people to start migrating to the Khorat Plateau during this time. The tribute to China was probably sent again in 750. Three years later, Wen Dan's crown prince, together with 26 relatives, visited the Chinese court, and the prince was given the title "Protector Firm and Persevering" for Wen Dan's assistance in helping to guard its southeastern frontier. Following the Tang dynasty's defeat in the trade routes conflicts by King Kolofong of Nanzhao in 753 and 755, Wen Dan's king dispatched his crown prince and generals to support China, but the Chinese armies were routed.

Due to several unsuccessful wars against Nanzhao, to strengthen the southern region, Jiaozhou was placed under a military commandant in 756. Ten years later, in 766, a Tang army of 70,000, led by General Li Mi from Sichuan, invaded Nanzhao. Vietnamese Governor "He Lu Guang" joined Wen Dan in attacking the south Nanzhao, but Kolofeng, the Nanzhao king, captured General Li and won. Wen Dan's army returned home. The following year, the citadel of Lo-than near the modern Hanoi was constructed after the region was raided by Malays of Champa, the viceroy of Wen Dan, with his wife, then came to court to pay 11 trained elephants. In 771, Wen Dan's prince went to China and was titled "Special Highest Local Commander," equal to the King of Nanzhao, and was even higher than the Chinese governors in Vietnam and Guangzhou. Another embassy is said to have been sent in 779, and the last one in 799. A Chinese merchant named Chia Tan paid a visit to the Wen Dan capital in the late 8th century. His itinerary for the journey also cursorily provides the location of Wen Dan, whose capital is potentially in the Chi River Basin in Thailand or near Thakhek in the present-day Laos.

No record mentions Wen Dan after the last tribute sent to China in 799. It was speculated that during this absent period, Wen Dan or Bhavapura was probably under the ancestors of Rajendravarman II, who, through his dynasty, later brought the kingdom under Yaśodharapura during his reign at Angkor from 944 to 968.

Angkorian period: 944 – 1300s

Despite having disappeared from the historical record since the early 9th century, Wen Dan or Bhavapura likely remained in its dependent status until Rajendravarman II, who was also of the Bhavapura house, was enthroned as the Angkorian king in 944. Through his lineage, Bhavapura was brought under Yaśodharapura during his reign, expanding the Angkor territory to Laos and the eastern Menam Valley in central Thailand, as far north as southern China – possibly through an alliance formation with local chiefdoms to defend against Nanzhao in the 8th century – and also won over Champa. Rajendravarman II was followed by his ten-year-old son Jayavarman V, during whose rule royal politics were dominated by aristocratic families, which led the kingdom to enter the nine-year civil wars, and the throne was then won by an usurper Suryavarman I in 1006.

Phra That Phanom Chronicle

Main article: Kuruntha

List of rulers

Name	Reign	Notes
Jayasimhavarmman	681 – 720s?	Bhavavarman (I?)'s relative. First tribute sent to China in 717.
Unknown	720s –740s	Allied with Nghean lord (Tai or Hmong) to capture Jiaozhou from the Chinese governer.
Unknown	740s – 770s	Allied with China against Nanzhao
Unknown	770s – 799?	Son of the previous, who assisted China in the wars against Nanzhao
Rulers before Mahendravarman II remains unknown.
Mahendravarman II?	Early 10th century	Father of Rajendravarman II
Rajendravarman II?	Early 10th century – 944	Later overthrew Harshavarman II at Koh Ker and claimed the throne of Angkor.
No records on Wen Dan after the 10th century; however, there are several semi-legenday Laotian polities, such as Kuruntha, Gotapura, Nong Han Noi (หนองหานน้อย), and Nong Han Luang, emerged in the Chi and Songkhram Basins, as cited in the Laotian Phra That Phanom Chronicle or Urangkhathat (อุรังคธาตุ), dated post-10th century.