Ketumāla
Ketumāla is presented in the Chronicle of Padumasūriyavaṁśa as a mythical 8th-century Dvaravati monarch whose biography is closely connected to that of Padumasūriyavaṁśa, who is described in the source as his adopted son and the inaugural ruler of the Siamese polity. According to this tradition, Ketumala was the son of Devavadī, a queen consort of Gomerāja, sovereign of Pranagara Khemarājadhānī. Following a prophecy foretelling misfortune, Devavadī and her infant son were compelled to depart from the royal court and subsequently established their residence upon the mound of Khok Thalok near Dong Phaya Fai Mountains. There, they asserted local authority, and the population of this nascent polity is said to have been composed chiefly of migrants from Pranagara Khemarājadhānī. Although Gomerāja repeatedly entreated Devavadī and Ketumala to return to the royal center, Ketumala consistently refused. Consequently, Gomerāja authorized his son to administer the region under the regnal title Śrī Ketumāla Mahākṣatriyaḥ and named the seat city as Indaprasthanagara, while Devavadī returned to Khemarājadhānī to rejoin her husband.
Ketumala is portrayed as having enjoyed a long reign marked by profound devotion to Buddhism, during which several surrounding polities were brought under his authority. In the absence of a biological heir, he adopted Padumasūriyavaṁśa and designated him as crown prince. During Ketumala’s reign, Padumasūriyavaṁśa is reported to have founded a new urban center situated east of present-day Sankhaburi. Following Ketumala’s death in 757 CE, he was succeeded by his adopted son, who chose to administer the polity from this newly established city rather than from Khok Thalok, the former royal seat. This new center subsequently inherited the name Indaprasthanagara from the earlier seat.
The latter parts of the Chronicle of Padumasūriyavaṁśa further endeavor to associate both Padumasūriyavaṁśa and Indaprasthanagara with the Angkorian sphere, an interpretation that contrasts markedly with the narrative preserved in the Ayutthaya Testimonies, wherein no connection to Angkor is mentioned. Moreover, the latter source asserts that Padumasūriyavaṁśa was in fact the adopted son of Subhattā, a figure situated in the east of Sankhaburi or Phraek Si Racha region. Subhattā is portrayed as having assisted Padumasūriyavaṁśa in securing the vacant throne of Indaprasthanagara. When these discrepant accounts are considered in tandem, and if Ketumala is to be identified with Subhattā, the locus of Khok Thalok may plausibly be situated within the eastern Phraek Si Racha area.