"Phra Ruang", the royal dynasty that once ruled the Sukhothai Kingdom and one of the royal family who ruled the early period of Ayutthaya. These stories are inserted in the history of Thailand for a long period.

Academics have assumed that belief in the sacred myth "Phra Ruang and His Supernatural Words' made people call the King of Sukhothai, "Phra Ruang" with admiration and loyalty.

There is no mention of the word to call the kings as "Phra Ruang" in the written evidence of Sukhothai such as any stone inscription, but the word "Phra Ruang" was found in the evidence of other contemporary regions with Sukhothai, such as Muang Phayao, Chiang Mai, or Kamphaeng Phet under the influence of Ayutthaya and also found in evidence during the period after the prosperity of Sukhothai, such as the Ayutthaya period and Rattanakosin period. Even the name of the royal family that governed Sukhothai, "Phra Ruang dynasty", was the result of efforts to systematize the monarchs' names to prevent confusion in the study, which occurred in the early Rattanakosin.

Many words which Sukhothai people referred to their monarch appearing in stone inscriptions changed, according to the period, such as "Pho Khun", "Phraya", as well as "the Great Dharma King", used as a name of the kings in the middle to late Sukhothai. This reflected the role of Buddhism in the monarchy while other regions still used the word "Phraya Ruang" to call noblemen from Sukhothai; therefore, the word "Phraya Ruang" was a unique identifier of the concept of Sukhothai people. And with this reason, Phra Ruang, the Sukhothai ruler, was the great dharma king. This obviously reflected the link of traditional beliefs with Buddhism which was prosperous in the Sukhothai period.