Borommatrailokkanat (บรมไตรโลกนาถ, bɔ̄ː.rōm.mā.trāj.lôːk.kā.nâːt, Brahmatrailokanātha) or Trailok (1431–1488) was the king of the Ayutthaya Kingdom from 1448 to 1488. He was one of many monarchs who gained the epithet King of White Elephants (พระเจ้าช้างเผือก). He was the first Thai king to possess a "noble" or white elephant, which, according to Hindu belief, was a "glorious and happy sign". His reign was also known for massive reforms of Thai bureaucracy and a successful campaign against the Lan Na Kingdom to the north. He was revered as one of the greatest monarchs of Thailand. Prince Ramesuan (not to be confused with King Ramesuan r. 1369–1370) was born in 1431 to King Borommarachathirat II or Chao Sam Phraya. Some authors claim that his mother was a princess of the Sukhothai Kingdom, daughter of Sai Lue Thai. According to historian Michael Vickery, however, this is not verifiable in historic sources and may be due to a misreading or misinterpretation of a chronicle. Be that as it may, Ramesuan was born at a time when the Kingdom of Sukhothai was increasingly tied to Ayutthaya, being under its suzerainty since 1412. When King Maha Thammaracha IV (Borommapan) of Sukhothai died in 1438, Borommaracha II of Ayutthaya annexed Sukhothai and installed his own son, then seven year old Prince Ramesuan, as viceroy (uparaja) of Sukhothai. When Ramesuan was 15 years old, the king sent him to Phitsanulok (which had replaced the city of Sukhothai as capital around 1430) to rule the former territories of Sukhothai which were now known as the "northern cities" (Mueang Nuea) and increase the control of the ruling family over them. Borommaracha II died in 1448, Prince Ramesuan was then crowned King Borommatrailokkanat of Ayutthaya, making a personal union between Sukhothai and Ayutthaya. Borommatrailokkanat reformed the Thai bureaucracy – the system lasted well into the 20th century. He separated civil and military officials, giving them titular ranks and feudal ranks to create the hierarchy of nobility, or life-nobles.