He began his reign as a vassal of the Bengal Sultanate, and successfully unified the entire Arakan coastline (present-day Rakhine State) in 1437.
He then took full advantage of the political turmoil in Bengal by seizing Ramu, the southernmost territory of his erstwhile overlord,[2][3] and raiding as far north as Chittagong.
[5] His 25-year reign brought much needed stability to the Arakan littoral, and prepared his nascent kingdom for future expansions by his successors.
[3] The earliest extant work of Arakanese literature in Burmese script, Rakhine Minthami Eigyin was composed during his reign in 1455.
[6] Born in 1392, Khayi was a son of King Razathu II of Launggyet Kingdom, located in present-day northern Rakhine State.
In November 1406, his half-brother King Saw Mon III was driven out by Avan troops led by Crown Prince Minye Kyawswa.
[4] However, the first confirmed successful occupation of Chittagong came only nine years later in 1459 when King Ba Saw Phyu seized the port from Sultan Rukunuddin Barbak Shah.
On 24 March 1455 (Monday, 6th waxing of Old Tagu 816 ME), Khayi and Narapati of Ava met and held a summit at Natyegan Hill past the An Pass.
Another son of his by Queen Saw Pyinsa, Min Swe, governor of Launggyet, was incensed by the selection, and fled to Kale (Kalay), a Shan state and a nominal vassal of Ava.
[16] The earliest extant work of Arakanese literature in Burmese script, Rakhine Minthami Eigyin ("Lullaby for a Princess of Arakan") appeared in 1455.