Sunthorathet

Phraya Sunthorathet Mahathepharat (), referred to in French sources as Ipoia Sanne Thora Thesma Teperat 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 () to Tasoo Nacora Louang (), also rendered as Yassouttora Nacoora Louang.

The precise identification of Tasoo Nacora Louang or Yassouttora Nacoora Louang remains contested among scholars. However, the European account Instructions Given to the Siamese Envoys Sent to Portugal (1684) states that Sanne Thora Thesma Teperat was succeeded by twelve monarchs from various ruling lineages, the last of whom, Pra Poa Noome Thele Seri (), moved the seat northward again to Soucouttae/Locontàï around 1188/89. Earlier, Pra Poa Noome Thele Seri had succeeded his relative Jatiraja at Mueang Sing, where seven successive monarchs had ruled before Jatiraja. This raises the possibility of identifying Mueang Sing with Yassouttora Nacoora Louang/Tasoo Nacora Louang.

Following Sunthorathet Mahathepharat's relocation, Srisimha moved his seat from Phetchaburi to Phraek Si Racha around the early to mid-11th century.