Popa Sawrahan

Popa Sawrahan () was the 20th king of Pagan Dynasty of Burma and the eighth king of "Tampavati period" of Bagan. He was notable for restarting the Burmese calendar in Bagan history and one of the two Sawrahan kings of Bagan Dynasty.
He was advised to reign over Pagan by his student, Queen Singharaj (). In 640 AD (562 Burmese Year), he encountered "Khachapañja kein" () or "The number needed to demolish year number". He subtracted 560 years from year 562, leaving a remainder of 2 years. Burmese people have been counting from the year two without restarting the calendar again.
Legend.
Sawrahan is the former monk seized the throne after King Htun Chit died in 613 CE. He launched the Burmese calendar on 21 March 640 CE, with the starting date of 22 March 638. (According to scholarship, the Burmese calendar was actually launched at Sri Ksetra (Pyay/Prome) by the Pyu.) 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.