Ipoia Sanne Thora Thesma Teperat

Ipoia Sanne Thora Thesma Teperat (Thai: พญาสุนทรเทศมหาเทพราช) is documented as the 11th monarch of Siam in the French work Du Royaume de Siam and in the Instructions Given to the Siamese Envoys Sent to Portugal (1684). His reign is marked by the relocation of the political center from Tchai Pappe Mahanacon (ไชยบุรีมหานคร) to Tasoo Nacora Louang (ธาตุนครหลวง), also rendered as Yassouttora Nacoora Louang.^{[1][2]: 127}

The precise identification of Tasoo Nacora Louang or Yassouttora Nacoora Louang remains contested among scholars.^[3] Should this new political center correspond to Lavapura of Lavo, the relocation would likely have occurred around the late 10th century, before it was sacked by Angkor in 1005. The Ayutthaya Testimonies recount the story of an early Siamese monarch named Intharacha (อินทราชา), which bears notable similarities to the account of Pra Poa Noome Thele Seri, the ruler of Phrip Phri mentioning in the Du Royaume de Siam and in the Instructions Given to the Siamese Envoys Sent to Portugal (1684), who is said to have undertaken a journey to Lavapura for several days to perform religious observances.^{[4]: 46–7} This narrative parallel may suggest—though cannot conclusively demonstrate—that Tasoo Nacora Louang, or Yassouttora Nacoora Louang, referred to Lavapura of Lavo.

Sanne Thora Thesma Teperat was succeeded by twelve monarchs drawn from various ruling lineages, the last of whom, Pra Poa Noome Thele Seri (พระพนมทะเลศรี), moved the seat again to the north to Soucouttae/Locontàï around the 1150s. Shortly thereafter, he, together with his younger brother Uthong I or Soi La (สร้อยหล้า), shifted southward into the western Menam valleys, where they reestablished Phrip Phri in 1188,^[1] and Uthong I is said to consolidate his authority by claiming the throne of Suphannabhum in 1163.^[5]: 61 In 1224, Pra Poa Noome Thele Seri further expanded his realm by annexing Chen Li Fu and Phraek Si Racha,^[5]: 21 while his son, Uthong II, asserted dynastic authority by claiming the throne of the Xiān's Ayodhya.^{[5]: 21 [6]: 41} Meanwhile, in the eastern valley, Lavapura was incorporated into the Angkorian sphere of influence, yet its status appears to have fluctuated over time. As Angkor’s authority weakened, Lavapura may have reasserted a measure of autonomy and sent occasional tribute to the Chinese court as a symbolic assertion of independence.^[a]