He was born in U Twa village. In his early life, he reportedly engaged in robbery and was involved in many murders. After being sold as a slave to a Christian Burmese, he was converted to Baptist Christianity by Adoniram Judson in 1828. he was called "Tha Byu" ("younger brother") by Judson when they first met. Judson recalls that Tha Byu was a vicious and angry person when they first met, and Tha Byu confirms this. After his conversion, though, Tha Byu became an energetic missionary to the Karen people. After twelve years, 1,270 Karen had been baptized, with many other believers.
- Clifford Kyaw De and Anna May Say Pa. "Tha Byu, Ko" A Dictionary of Asian Christianity. Scott W. Sunquist, editor. Michigan: Wm B Berdmans Publishing Co. 2001.
- Francis Mason. Ko Tha Byu, the first Karen Christian (1983)
- (in Karen languages) Ya Ba Toh Loh. Life of Saw Ko Tha Byu (1950)