Introduction
Saw O (Burmese: စောအော, pronounced: [sɔ́ ʔɔ́]; 1283–1323) was the third king of the Hanthawaddy Pegu from 1311 to 1323. Saw O succeeded his maternal uncle Hkun Law, who was assassinated by Saw O's father Min Bala in 1311. When Saw O ascended to the throne on 10 April 1311 (Saturday, 6th waning of Tagu 673 ME), his kingdom was a nominal vassal of Sukhothai. He was even married to a daughter of the king of Sukhothai. But as the power of Sukhothai declined, Saw O took possession of the Tenasserim coast from his nominal overlord Sukhothai.
His reign was largely peaceful and prosperous, and the kingdom's northern frontier was quiet. (Unlike Lower Burma under a single kingdom, Upper Burma remained disunited, split among petty kingdoms. None of the Upper Burmese kingdoms was in a position to make war with a unified south.) However the king's desire to be independent of Sukhothai led to future wars between the two kingdoms.
Saw O died in September 1323, and was succeeded by his brother Saw Zein.
Background
Like his predecessors, Saw O was also of Shan and Mon descent. (He was at least a quarter Shan as his mother Hnin U Yaing, sister of King Wareru, was half-Shan. Part of his name Saw was the Shan honorific Sao.)
He had a son Saw E (future king) and a daughter with Princess of Sukhothai.