Suryaraja
Suryaraja, son of Suryavamsa, was a Siamese monarch mentioned in the Ayutthaya Testimonies as the ruler of Vicitraprakāra, a polity identified with the present-day Kamphaeng Phet. A descendant of King Padumasuriyavamsa, Suryaraja was recorded to have relocated to Vicitraprakāra in 1156 CE, where he established his principal seat of power. He ascended the throne at the age of twenty and reigned over the polity for a period of twenty-eight years. Suryaraja’s northward relocation coincided with the reconsolidation of the lower Menam basin in 1157 CE under Sri Dharmasokaraja II, whose authority in the region appears to have continued until approximately 1180, when Angkorian expansion extended both military and political influence into the area.
Suryaraja’s authority may have extended to Sukhothai, as Michael Smithies has tentatively proposed that Pra Poa Noome Thele Seri—whose dynasty, like that of Suryaraja, descended from King Padumasuriyavamsa —relocated northward from Yassouttora Nacoora Louang to establish his dominion at Sukhothai–Lacontai in the mid-1150s. It has been further suggested that he may have belonged to the same royal lineage as Si Intharathit, the grandson of Suryaraja, who later ascended the throne of the Sukhothai Kingdom in 1238. Pra Poa Noome Thele Seri and his younger brother, Uthong I of Mueang Chaliang, were subsequently said to have moved southward to consolidate their authority in the western Menam valleys around 1156–1157 CE, a timeframe that corresponds closely with the calculated date of Suryaraja’s enthronement at Kamphaeng Phet.
Suryaraja was married to Sirisudhārājadevī, with whom he had a son named Candraraja. The latter subsequently ascended to the throne as ruler of Vicitraprakāra–Sukhothai, reigning from 1184 to 1214.