Arunaraja

Aruṇarāja (, ), also rendered as Aruṇa Kumāra (, ) and traditionally identified as Phra Ruang I , was a mixed Mon–Tai monarch recorded in the Northern Chronicle as a ruler of both Mueang Chaliang (Si Satchanalai) and Sukhothai. He was born to King Abhayakāminī of Sukhothai—who was of Mon descent from Haripuñjaya—and Nang Nak, a Tai consort from Nan of Ngoenyang. Around the mid-950s CE, Aruṇarāja, at the age of 40, was appointed by his father to govern Mueang Chaliang through marriage to the princess of the preceding ruler, Sudhammaraja, who had no male heir.

According to later records, Aruṇarāja took as his queen consort a princess Rājakalyāṇī of the Chinese Emperor, although there exists no surviving documentation concerning their offspring. It is further recorded that five hundred Chinese attendants who accompanied the princess settled permanently in Mueang Chaliang, leading to the establishment of enduring trade relations between Chaliang and China. Aruṇarāja had two younger half-brothers: Ṛddhikumāra , the ruler of Mueang Pichai Chiang Mai —identified in some accounts with or Kampoṭanagara —and the youngest, Suvacanaraja, who succeeded Aruṇarāja upon his death in 1052 CE. The succession, however, may have taken place earlier than the extant narrative asserts, as the reign length attributed to Arunaraja appears implausibly protracted. According to the account, his rule commenced in the 950s, when he was approximately 40 years old, and concluded in 1052. This would imply a lifespan approaching 140 years at the time of his death—an evident chronological impossibility.

The reign of Aruṇarāja was notably characterized by his patronage of Buddhism, as reflected in the chronicle, wherein his principal duties are described as being largely connected to religious and monastic affairs. His political acumen is further evidenced by his strategic decision to arrange the marriage of his brother to the princess of , thereby extending the political influence and territorial authority of Mueang Chaliang.