Bayin Htwe is the eldest son of Thado Minsaw of Prome, who had proclaimed the independence of his minor kingdom from Ava in 1482.

Htwe had ascended to the throne in 1526 after his father's death.

The new king had soon incurred the wrath of Sawlon, the leader of the Confederation of Shan States, because he did not send help in the Confederation's war against Ava in 1526–1527.

His father had been an ally of Sawlon, and had sent troops in their 1524–1525 assault on Ava.

In 1532, Sawlon and his Confederation armies (twelve thousand troops, eight hundred horses and thirty elephants) laid siege to Prome (Pyay).

Bayin Htwe had surrendered in late 1532, and had been sent to Dabayin in Upper Burma in exile.

Htwe's son Narapati was appointed vassal king.

Htwe's life in captivity is cut short after Sawlon is assassinated by his own ministers near Myedu, enabling his return to Prome.

He arrives back at the outskirts of Prome, five months after he lost his throne, but his son does not allow him back in the city.

He dies about a month later in the adjoining forests.

His legacy will live on through his offspring.

Two of his sons, Narapati and Minkhaung, become rulers of Prome, albeit as vassals of Ava.

Two of his daughters, Salin Mibaya and Laygyun Mibaya, will be married to Thado Dhamma Yaza II of Prome and Minkhaung II of Toungoo, who respectively will become viceroys of Prome and Toungoo.

He is the maternal grandfather of Queen Hsinbyushin Medaw of Lan Na and Queen Min Taya Medaw, a principal queen of King Nanda of the Toungoo Dynasty.

Narapati has remained a nominal vassal to Confederation-controlled Ava.

Although his authority does not extend beyond the immediate region around Prome, he has become ensnarled in the Toungoo–Hanthawaddy War.

An ally of King Takayutpi of Hanthawaddy, Narapati is married to Takayutpi's sister, and provides shelter to the fleeing Hanthawaddy troops in 1539.

When Toungoo troops attack the heavily fortified Prome, Narapati asks for help from the Confederation in Ava, which has neglected to intervene in the first four years of Toungoo–Hanthawaddy Wa in Lower Burma.

Now finally appreciating the gravity of the situation, the saophas finally band together and send in a force to relieve Prome.

The Confederation troops break the siege, then refuse to follow up on the retreating Toungoo armies.

Narapati forms an alliance with the Mrauk U Kingdom of Arakan by sending his sister and his queen (Takayutpi's sister) to King Min Bin of Mrauk U.

(Takayutpi had died soon after the battle.)

Narapati too dies soon after and is succeeded by Minkhaung.

Min Bin has turned Mrauk-U into a serious regional power by the late 1530s.

Not only does he control the entire Arakan littoral to Chittagong but he also has built up a powerful navy and an army that includes many Portuguese mercenaries.

He closely monitors the developments in mainland Burma with great concern, however,especially after Toungoo's unlikely victory over Hanthawaddy that gives upstart the upstart Burmese principality control of Lower Burma.

He does not want to see a strong, united Irrawaddy valley, which in the past had interfered with the coastal kingdom.

When King Minkhaung of Prome, the only holdout in Lower Burma and a vassal of the Confederation of Shan States, asks for an alliance by presenting his sister, the former queen of Hanthawaddy, Min Bin readily agrees.

Pegu becomes the capital of Tabinshwehti’s united Burmese kingdom in 1539.