Khom Sabat Khlon Lamphong

Khom Sabat Khlon Lamphong (Thai: ขอมสบาดโขลญลำพง), possibly identifiable with Thao Saen Pom and Phra Ruang III, was a 13th-century monarch attested in the Wat Si Chum Inscription as the ruler of Sukhothai–Si Satchanalai. Earlier scholarship identified him as a Khmer noble appointed by Angkor to administer the region; however, more recent interpretations propose that he was a kinsman of his predecessor, Sri Naw Nam Thum, and nevertheless maintained political affiliations with Lavo.

Khomsabat Khlon Lamphong succeeded Sri Naw Nam Thum, either following the latter's death or through forcible usurpation. Subsequently, he was deposed in 1238 by a coalition force led by Si Inthrathit, the ruler of Mueang Bang Yang (son of Candraraja, the former sovereign of Sukhothai) together with Pha Mueang, a Tai Lueang (ไทเลือง) monarch of Mueang Rat. Following Khomsabat Khlon Lamphong's deposition, Si Inthrathit was enthroned as the new ruler. This event has been conventionally interpreted in historiography as marking the formal inception of the early Siamese polity; nevertheless, various historical records attest that the Siamese had already exercised political authority over Sukhothai prior to this episode.

On etymological grounds, certain scholars have identified Khom Sabat Khlon Lamphong with Thao Saen Pom, a legendary figure reputed to have married a Tai Yuan princess of Mueang Tri Trueng and subsequently migrated southward to assume the vacant throne of Suphannaphum around the mid-13th century. His successor, Uthong (III), is said to have consolidated dynastic authority in the region and later established a royal alliance with the Siamese polity at Ayodhya through the marriage of his daughter to Uthong (V), the first monarch of the Ayutthaya Kingdom. This lineage is generally identified in later historiography as the Suphannaphum dynasty.

Moreover, during the same period, Si Inthrathit (Phra Ruang IV) of Sukhothai is recorded in the Legend of Sawankhalok as having an elder brother, likewise named Phra Ruang (III). While the younger prince Si Inthrathit was assigned by his father Candraraja to ruled Mueang Bang Yang, his elder brother Phra Ruang III was sent to rule Mueang Fang (เมืองฝาง), commonly identified with present-day Sawangkaburi. This polity situated in the same area as Mueang Tri Trueng of Thao Saen Pom. If these three figures—Khom Sabat Khlon Lamphong, Thao Saen Pom, and Phra Ruang III—are understood as representing a single historical individual referred to under different names or titles in distinct sources, then the alliance between Si Inthrathit and Pha Mueang that led to the overthrow of Khom Sabat Khlon Lamphong in 1238 may be reinterpreted as an intra-dynastic power struggle between the two brothers.