| Sai Thong Som ใสทองสม | |
|---|---|
| King of Devapura | |
| King ofDvaravati'sKamalanka | |
| Reign | 687–late 8th-c. |
| Predecessor | Shridravya |
| Successor | Pú jiā yuè mó |
| Born | Lopburi |
| Died | Late 8th-c. |
| House | Lavo dynasty |
| Father | Balidhiraja ofSukhothai |
Sai Thong Som (Thai:ใสทองสม) is traditionally identified as a mixedMon–Tai monarch ofDvaravati's Devapura (เทพบุรี) or Rajgir (ราชคฤห์),[1]: 4 which modern scholarship variously associates withNakhon Pathom,Ratchaburi, orKhu Bua.[1]: 5 His reign is attested in theLegend of the Arhat (Tamnan Nithan Phra Arahant;ตำนานนิทานพระอรหันต์), a chronicle compiled by Aung Wailamlang (อ่อง ไวกำลัง). According to this account, his father,Balidhiraja—a son ofKalavarnadisharaja—migrated fromSukhothai and forcibly deposed the incumbent monarch of Devapura around 687 CE. The throne was subsequently entrusted to his younger son Sai Thong Som.[1]: 3–4
Sai Thong Som is recorded as having had one sibling, his elder brotherBalipatijaya, who acceded to the throne ofLavo in 700 CE, following the reign of their grandfatherKalavarnadisharaja.[1]: 4 On the basis of onomastic analysis, the Thai historian Manit Vallibhotama (มานิต วัลลิโภดม) has suggested that Sai Thong Som may have been born of aTai queen consort.[1]: 5 This interpretation gains plausibility in light of the historical context: afterKalavarnadisharaja’s enthronement as king ofLavo, he is reported to have extended his political influence northward into the Tai polity ofChiang Saen,[1]: 5 which is mentioned as Nagendhara (นาเคนทร) in theNorthern Chronicle [th].[2]: 25 It is within this framework of political expansion and consolidation that intermarriage between the Mon dynasty of Dvaravati and Tai elites likely occurred, cementing alliances through marital diplomacy and reshaping the ethnopolitical configuration of the region.[1]: 5 By the mid-9th century, this dynamic had intensified; in 861 CE, records note that theTai Yuan, or Tai Chiang Saen (ไทเชียงแสน), had established a significant presence in Lavo and were increasing in political influence.[3]: 39
No definitive records survive concerning Sai Thong Som’s immediate successor. Nevertheless, archaeological and textual data suggest that by the early 8th century, corresponding with his reign, the political predominance ofDvaravati had entered a phase of decline.[4]: 60 Chinese sources,Cefu Yuangui, identify the westernMenam Valley in the late 8th century as belonging to the polity ofGē Luó Shě Fēn (哥罗舍分国),[5]: 38–9 likewise centered atNakhon Pathom.[4]: 58–9 Some scholars have hypothesized thatGē Luó Shě Fēn andQiān Zhī Fú ofSi Thep were, in fact, the same kingdom,[5]: 38–9 which during this period was reportedly ruled byPú jiā yuè mó.[6]: 23 Despite this apparent fragmentation of authority, the Chinese dynastic records note that Dvaravati continued to maintain tributary relations with the Tang court, with the last mission being dispatched in 756 CE.[7] This episode illustrates both the persistence ofDvaravati’s diplomatic identity and the gradual contraction of its political power. Ultimately, the emergence ofGē Luó Shě Fēn curtailed the territorial reach of the Dvaravati monarchs, restricting their authority largely toLavapura of theLavo in the eastern valley, which was governed byBalipatijaya from 700 CE onward.[1]: 4