The three brothers ruled as co-regents from their respective capitals in Kyaukse district, Athinhkaya from Myinsaing.
Founded in 1364, the kingdom was the successor state to the petty kingdoms (Myinsaing– Pinya and Sagaing) that had ruled central Burma since the collapse of Pagan Empire in the late 13th century.
In December 1297, the brothers formalized their rule of central Burma by forcing the nominal king of Pagan Kyawswa, who had become a Mongol vassal, to abdicate the throne, and ruled as co-regents from their respective palaces in Myinsaing, Mekkara and Pinle.
Thihathu of Myinsaing consolidated his control of central Burma in April 1310, and moved his capital to Pinya in February 1313.