Suvarnaraja (), the seventh monarch of XiÃÂn at Ayodhya, ascended the throne following the death of his adopted father and paternal uncle, Jayasena. His reign, from 1289 to 1301, was marked by strategic military campaigns aimed at consolidating XiÃÂnâÂÂs influence over the southern regions on Melayu, Tanmayang, and Sumatra, as well as projecting power eastward toward Angkor.
Suvarnaraja's campaigns against Angkor in the 1290s have prompted scholarly debate regarding the extent of Angkorian authority over intermediary polities, particularly Lavo. Evidence suggests that Lavo may have attained de facto autonomy by the 1280s, as indicated by Chinese records of significant XiÃÂn settlements in Lavo, as well as its tributes sent to China in 1289 and 1299.
Suvarnaraja was succeeded by his sons-in-law, Dhammaraja in 1301 and Baramaraja in 1310, both of whom maintained and extended Suvarnaraja's military and political strategies toward Angkor and other polities in the lower Malay Peninsula. The continuity of these policies illustrates a deliberate approach to regional power projection and state consolidation, which ultimately culminated in the traditional foundation of the Ayutthaya Kingdom by BaramarajaâÂÂs son, Uthong V, in 1351.
SuvarnarÃÂja was the son of Jayadatta (), an elder Tai prince of Phichai Chiang Mai or Phetchaburi, who, according to the Thai Northern Chronicle, engaged in a clandestine relationship with Rajadevi, the only daughter of Uthong II. This transgression ultimately led to JayadattaâÂÂs execution at the hands of Uthong II. When it became known that the princess was pregnant, SuvarnarÃÂja's younger brother, Jayasena, was compelled to marry her. Jayasena succeeded his father-in-law in 1253 and reigned until 1289. Following the death of his own father, in the same year, Jayasena abdicated the throne of Ayodhya in favor of his adopted son, SuvarnarÃÂja, and returned to govern Phichai Chiang Mai.
SuvarnarÃÂja reigned at Ayodhya from 1289 to 1301. He had two daughters, Princess KalyÃÂdavë () and Princess Sunandhadevë (). KalyÃÂdavë was married to Prince Dhammaraja, and Sunandhadevë to the younger, Prince BaramarajaâÂÂboth princes under King Dhammatriloka of Si Satchanalai. Upon SuvarnarÃÂjaâÂÂs death in 1301, Dhammaraja ascended the throne of Ayodhya and ruled until 1310, after which his brother Baramaraja reigned from 1310 to 1344.
Following the completion of his conquest of China, Kublai Khan initiated plans to extend Yuan suzerainty over several polities in mainland and maritime Southeast Asia. To this end, he frequently dispatched embassies whose rhetoric was characterized by imperious demands for submission, as exemplified by his missions to the Burmese court.
The earliest recorded interaction between XiÃÂn and the Yuan dynasty occurred in 1282, during the reign of Jayasena, the predecessor of Suvarnaraja. On that occasion, a Yuan naval embassy led by He Zizhi was dispatched to XiÃÂn; however, the mission failed as the envoys were intercepted and executed by Cham forces, then engaged in hostilities with China. A decade later, in November 1292, XiÃÂn dispatched an embassy to the Yuan court at Canton (Guangzhou), thereby initiating formal diplomatic relations. Two years subsequently, in 1294, XiÃÂnâÂÂidentified in contemporary records with Phrip PhriâÂÂagain sent envoys under the authority of Uthong II's son, Sam (). In response, the Yuan emperor issued an order demanding either the kingâÂÂs personal attendance at court or the provision of hostages, a demand that was initially declined.
Despite such initial refusal, the Yuan court reiterated its demand in the same year, after which the monarch of XiÃÂn complied by appearing at the imperial court and rendering tribute in the subsequent year. The final recorded tribute mission from XiÃÂn during the reign of Suvarnaraja occurred in 1299; however, the embassyâÂÂs request for reciprocal gifts from the emperor was explicitly rejected.
In 1295, records indicate that the polity of Melayu submitted a formal complaint to the Yuan court, reporting that it had been subjected to sustained military aggression by XiÃÂn over a period of several years. In response, the Yuan emperor issued an order directing XiÃÂn to cease hostilities against Melayu. Beyond these campaigns, XiÃÂn also launched incursions into Tanmayang, identified with present-day Singapore.
To the east, Angkor likewise endured significant military pressure from XiÃÂn. During the reign of Jayavarman VIII (r. 1243âÂÂ1295), Angkor was reportedly devastated by a major XiÃÂnese invasion. This conflict is corroborated by Zhou Daguan, the Yuan envoy to Angkor, who recorded in The Customs of Cambodia that, by 1296, Angkor under Indravarman III had been engaged in prolonged warfare with XiÃÂn, leaving the kingdom in a state of severe devastation.
Between circa 1297 and 1301, historical sources record a military confrontation in which the Samudera Pasai Sultanate, situated in northern Sumatra, faced an incursion against the polity identified as XiÃÂn. The campaign culminated in the death of the Pasai sultan, yet XiÃÂn itself incurred severe losses and was compelled to withdraw.
Earlier historiographical traditions frequently equated XiÃÂn with the Sukhothai Kingdom; however, this identification has been conclusively refuted. The Dade Nanhai-zhi (), compiled in 1304, explicitly distinguished the two entities, designating Sukhothai as Sù Gà « Dà() and noting its subordination to XiÃÂn, which exercised jurisdiction over the upstream territory (, ). Moreover, records from 1299 indicate that both XiÃÂn and Sù GàChà(), another appellation for Sukhothai, dispatched distinct tributary embassies to the Yuan court. The simultaneous recognition of both polities as separate tributary states provides unequivocal evidence that XiÃÂn and the Sukhothai Kingdom were not synonymous.