Wikipedia
Athittayawong
Athittayawong (; born 1618) King Athitayawong was the shortest-reigning monarch of Ayutthaya, only for 36 days in 1629 and the last king of the Sukhothai dynasty."
Prince Athitayawong was the son of King Songtham and his principal wife. His elder brother, King Chetthathirat and his mother were executed in 1629 after Okya Siworawong or Phraya Siworawong staged a coup.