Singhanavati

There is evidence of human habitation in present-day Chiang Saen district in the Neolithic age but no other contemporary evidence to connect them with the pre-historic period and the modern northern settlements.^[1]: 13 Few prehistoric artifacts were found to be linked with the ancient Haripuñjaya Kingdom, but further historical and archaeological study had additionally been needed to illustrate.^[1]: 14

Before the establishment of Singhanavati, the area was previously occupied by Austroasiatic peoples,^[5] especially the Khmu people.^[6] The preexisting principal city-state located on the right bank of the Mekong River opposite to the present-day Chiang Saen was believed to be another legendary kingdom, Souvannakhomkham (สุวรรณโคมคำ), which its descendant later moved to Umongasela (อุโมงคเสลา) in the present-day Fang after Souvannakhomkham was submerged into the Mekong River.^{[5]: 187, 283 [7]}

According to the legend of Singhanavati, the city of Yonok Nagaphan was established near the submerged Souvannakhomkham by Prince Singhanavati who immigrant from southern China in 691 BCE, 148 years before the death of Buddha,^[1]: 8 which was the transition of the late Bronze Age to the Iron Age.^[1]: 9 This migration legend was supported by a bronze drum found in the wetland near Chiang Saen that was probably the submerged Yonok city; the artifacts were also discovered scattered along the river basins from southern China, Mekong valley, and northwestern Vietnam.^[1]: 9 However, in the 2009 archaeological excavations performed by the Fine Arts Department of Thailand, no ancient structures dating before 545 CE were found in the area, ^[1]: 9 which was considered the period when the city was submerged below the Chiang Saen Lake due to an earthquake.^[2][3][8] Formerly, most historians suggested that the city of Yonok Nagaphan was probably established in 545 CE and fell around 1107–1109.^[2][3][8] This due to the complicated era systems mentioned in the chronicles which comprised three systems: the Boran era (lit. 'Ancient era'; probably the Añjana's Era), the Buddhist Era, and the Shaka era, but the given years in the chronicles were not directly specified.^[6] After the chronicle that gave more details than the preexisting was found in the Wat Ban Rong Bong in 2022, it was concluded that the events mentioned in the legend of Singhanavati happened before 638 CE and all historical records related to the legend were then revised.^[6]

The Singhanavati Kingdom subjugated the preexisting Umongasela, and other nearby states to extend its territory. However, during the reign of Pangkharat [th] in the mid-4th century, the seat at Yonok was forcibly lost to King Khom from Umongasela. Pangkharat fled to Vieng Si Tuang (เวียงศรีทวง; present-day Wiang Phang Kham, Mae Sai district) but had to send tributes to Yonok annually until his son, Phrom (361–438), took back Yonok in 377 and expelled Khom from Umongasela.^[9][10][11] Phrom also led the army went to suppress the King Khom troops as far as the territory of Chakangrao in the south,^[9] along with establishing a new town in 396 to be an outpost to prevent enemy invasion in the old Umongasela area and renamed it Chai Prakan.^[12] While the throne at the capital Yonok was given to his older brother, Thukkitakuman [th].^[13] His son Chaiyasiri, continued to rule Chai Prakan;^[14] however, after the fall of Yonok, Chayasiri, along with many of his subjects, moved south to settle in the present-day Nakhon Thai, Phitsanulok Province. According to Simon de la Loubère, Chaiyasiri, who was speculated to be the Singhanavati lineage, is said to have built the city of Pipeli [th] in Phetchaburi Province,^[15] but the dates are not related.

Before the reign of Pangkharat [th], which is considered its peak, the influenced area reached present-day Yunnan in the north and the upper Chao Phraya River valley in the south, while the east met the Annamite Range and the Salween River in the west.^[16]

The last king of the Singhanavati Kingdom was Thukkitakuman [th]. During his reign, Yonok was submerged into the Chiang Saen Lake because of an earthquake in 545.^[17] The survivors, led by Khun Lung, went east to settle at Vieng Prueksa [th] and the remaining principalities, which consisted of fourteen chiefdoms, formed the chamber to select new rulers. The chiefdoms lasted for 93 years with the said elective monarchy. After this period, the records mention the development of high land communities at Doi Tung led by Lavachakkaraj [th],^[18] who later became the ruler of Vieng Prueksa in 638. Lavachakkaraj also renamed the city of Vieng Prueksa to Hiran which is considered the beginning of the Ngoenyang Kingdom and continued through the founding of the Lan Na Kingdom at the end of the 13th century.^[19]

During this period, in the south of Vieng Prueksa, another principality Haripuñjaya was founded in the Ping River valley in 629 by the legendary Suthep, who has then invited Monic princess, Camadevi, from the southern kingdom of Lavo to rule the city in 662; thus Lavo began expanding its influence in the north.

Simon de la Loubère's record refers to the first Siamese king, named Phra Pathom Suriyathep Norathai Suvarna Bophit (Thai: พระปฐมสุริยเทพนรไทยสุวรรณบพิตร, Pra Poat honne sourittep-pennaratui sonanne bopitra). The chief place where he kept his court was called Chai Buri Mahanakhon (Thai: ไชยบุรีมหานคร, Tchai pappe Mahanacon), and his reign began in 757. Ten other kings succeeded him, the last of whom was named Phaya Sunthorathet Mahathepparat (Thai: พญาสุนทรเทศมหาเทพราช, Ipoja sanne Thora Thesma Teperat), removed his royal seat to the city of That Nakhon Luang (Thai: ธาตุนครหลวง, Tasco Nacora Louang; but Diplomatic guide referred to Yasothonpura Nakhon Luang (Thai: ยโศธรปุระนครหลวง, Yassouttora Nacoora Louang^[20]: 127)) which he had built but the location is uncertain.^[15]

Later in 1188, the 22nd king after Phaya Sunthorathet, whose name was Phra Phanom Chaiyasiri (Thai: พระพนมไชยศิริ, Pra Poa Noome Thele seri), obliged all his people to follow him to Nakhon Thai (Locontai; but "Diplomatic guide" referred to Sukhothai (Thai: ศุโขทัย, Soucouttae^[20]: 127)). This prince did not always reside at Nakhon Thai, but instead, he built and inhabited the city of Phetburi (Pipeli). Four other kings succeeded him; of which Ramadhiboti (Rhamatilondi), the last of the four, began to build the city of Ayothaya in 1351, and there he established his court. “By which it appears, that they allow to the City of Ayutthaya the Antiquity of 338 years. The King Regent is the twenty-fifth from Ramadhiboti, and this year 1689, is the 56th or 57th year of his age. Thus do they reckon 52 Kings in the space of 934 years, but not all of the same blood lineage.”^{[15][21][20][22]}

Through the Theravada, the relationships between the southern principality, Tambralinga, during the reign of Chandrabhanu (r.1230–1262) and the Siamese leaders in the north of the Kra Isthmus was speculated to have begun after the foundation of Phetburi (Pipeli).^[23]: 292 which was expected to be one of the reasons that Srivijaya lost influence over Tambralinga.^[23]: 298