Mandalay Bo Daw was of Ponna descent who had tended, taught and looked after shwe Phyin Nyi Naung brothers in their boyhood. So they called him Grandpa. During King Anawrahta’s reign he became a minister.
Infact Shwe Phyin Nyi Naung being fatally punished happened to be primarily due to the fact that the guardian minister’s way of teaching, tending and upbringing were merely wrong and defective for which he was fully responsible, teaching false lesson is a punishable offence. Getting wind of taking action against him the old man Bo Daw tried to run away with his elephant was caught red-handed just before absconding. The penalty inflicted on him was punishable by death, thus immediately after execution he became a Nat of Mandalay Bo Daw.