The small town was not only the ancestral home of the dynasty but also served as U's wartime capital from 1364 to 1369 when the king was driven out by Byattaba's forces.
About 700 rebel troops entered the town disguised as mourners of Chief Minister Pun-So, who had just died.
He gave Donwun to Sam Lek as a fiefdom,[1][4] and awarded him the royal regalia befitting a viceroy.
The rebel brothers agreed to acknowledge U as their overlord in exchange for U's recognition of their de facto independent rule.
[5] Sam Lek proved a rare loyal vassal even when U gradually withdrew from governing the kingdom due to deteriorating health in later years.
When U's eldest son Binnya Nwe revolted in 1383, Sam Lek remained firmly in the ailing king's camp.
When Ava did not invade in the dry season of 1387–1388, the first place Razadarit and the Pegu court looked to deploy their already mobilized forces was the northern Martaban province.
When Razadarit's armies conquered the northern province and showed up before Donwun's walls, Sam Lek, confident that his heavily fortified town could withstand the attacks, simply reneged on the pledge.
Razadarit sent Commander Smin Ye-Thin-Yan, a childhood friend and thwethauk[note 6] comrade of Sam Lek, pretending to have defected with 300 men.
Ye-Thin-Yan convinced him that he had stolen loads of gold and silver from the king, and that his men would enter Donwun without any arms.
At a predetermined time, Razadarit's forces from outside the town and Ye-Thin-Yan's men from the inside launched a coordinated attack.
[13] Nevertheless, Razadarit took Sam Lek's daughter May Hnin Kaythaya, who was already married,[11] as a concubine before giving her to Commander Lagun Ein.