He was advised to reign over Pagan by his student, Queen Singharaj (သင်္ဃရာဇ် မိဖုရား).
Sawrahan is the former monk seized the throne after King Htun Chit died in 613 CE.
[Note 1] (According to scholarship, the Burmese calendar was actually launched at Sri Ksetra (Pyay/Prome) by the Pyu.
[2]) Popa Sawrahan made peace with the royal line by giving his daughter to Shwe Ohnthi, son of Htun Chit and rightful heir, and making his son-in-law the heir apparent.
Popa Sawrahan died in 640 soon after his new calendar was launched, and Shwe Ohnthi succeeded, restoring the Pyusawhti line.