Prince Yot Fa was the oldest son of King Chairacha (r. 1534-1547) from the House of Suphanburi and the royal concubine Thao Si Sudachan.
King Yot Fa succeeded the throne at the age of ten [3] or eleven [1] depending the sources.

Due to his young age he was unable to manage the Royal affairs and Prince Thianracha and Tao Sri Sudachan, King Chairacha's non-royal
concubine, acted as regents. Some conflicts between the latter two arose and Prince Thianracha entered the monkhood, leaving the State affairs to
Tao Sri Sudachan. The latter committed adultery and with intrigues arranged that her lover (with the title Worawongsa) became Regent.

The exact cause of the death of King Yot Fa in 1548 remains unknown. Following the Luang Prasoet Chronicle he got an accident. The later
written Royal chronicles of Ayutthaya state that King Yot Fa was executed at the
Khok Phraya Monastery [1]. The contemporary Portuguese
traveler Pinto although, wrote the young king was poisoned by Khun Worawongsa. Van Vliet in his "Short story of the Kings of Siam 1640"
mentioned also poisoning but by his mother "Mae Si Suda Chao" [3].


[1] The Royal Chronicles of Ayutthaya - Richard D. Cushman (2006) / Source: Luang Prasoet, Phan Canthanumat, British Museum, Reverend
Phonnarat, Phra Cakkraphatdiphong & Royal Autograph.
[2] A History of Siam - W.A.R. Wood (1924).
[3] Van Vliet's Siam - Chris Baker, Dhiravat Na Pombejra, Alfons Van Der Kraan & David K. Wyatt (2005).