Prome had been a vassal of the Ava kingdom for centuries, a strategic frontier post on the border with the rival Hanthawaddy kingdom to the south. The Forty Years' War between Ava and Hanthawaddy, fought from 1385 to 1424, ended in a stalemate that left Ava exhausted and its vassals restless. Avan kings appointed only their most senior princes as viceroys of Prome -- Crown Prince Minye Kyawswa, King Thihathu, and King Narapati all served in the role. But by the 1460s, loyalty was fraying. In 1469, Prome's longtime governor Mingyi Swa rebelled against his own brother when the latter took the Ava throne as Thihathura. The king besieged Prome and Mingyi Swa submitted, receiving a pardon and his old post back. When both Thihathura and Mingyi Swa died within two years of each other, their successor Minkhaung II faced rebellions on all sides. Thado Minsaw, the governor of nearby Tharrawaddy and Mingyi Swa's brother, saw his chance. In 1482, he seized Prome and declared himself king. Ava sent an army to retake the city but failed, and with the Yamethin rebellion and Shan uprisings consuming its resources, never tried again.

Thado Minsaw proved shrewder than his violent rise suggested. Rather than picking fights with his neighbors, he kept Prome out of the wars consuming Upper Burma and forged a peaceful relationship with Hanthawaddy, the most powerful kingdom in the region. His territory stretched from Prome south to Tharrawaddy and Myede -- modest holdings, but enough to sustain an independent court. For nearly four decades, while Ava bled itself dry against the Confederation of Shan States, Prome thrived in relative quiet. It was a strategy of calculated restraint, and it worked as long as the balance of power around it held.

In the 1520s, Thado Minsaw abandoned restraint. Ava was dying -- the Confederation of Shan States, a coalition of highland warlords, had been hammering the kingdom for years. Thado Minsaw entered into a league with Sawlon, the Confederation's leader, and in March 1525, their combined armies sacked the city of Ava itself. King Shwenankyawshin, Thado Minsaw's own grandnephew, barely escaped. Prome and Confederation soldiers looted the ancient capital. Among the treasures carried back to Prome was the famed poet monk Shin Maha Rattathara -- a human prize that spoke to Prome's cultural ambitions as much as its military ones. Thado Minsaw died in 1526, his legacy a paradox: a prudent ruler who, in his final years, helped destroy the very kingdom his family had once served.

Thado Minsaw's son Bayin Htwe inherited an alliance that had curdled. On March 25, 1527, Confederation forces captured Ava and installed Sawlon's eldest son Thohanbwa on the throne. Sawlon resented Prome's insufficient support during the campaign and harbored a grudge. In 1532, Confederation armies attacked Prome, took Bayin Htwe prisoner, and dragged him north. After Bayin Htwe's escape and betrayal by his son Narapati, Prome shrank to a rump state controlling little beyond its own walls. Narapati was drawn into the Toungoo-Hanthawaddy War as an ally of King Takayutpi of Hanthawaddy, sheltering fleeing soldiers and marrying into the royal family. He formed a last alliance with the Mrauk U kingdom of Arakan, sending his sister and queen to King Min Bin. But Narapati died before this coalition could bear fruit.

In late 1541, the rising Toungoo dynasty besieged Prome for the final time. The last king, Minkhaung, called on both his allies -- the Confederation sent troops from Ava, and Mrauk U dispatched an army and a naval flotilla that landed at Bassein. It was not enough. Toungoo forces under General Bayinnaung defeated both relief armies in sequence. When the Mrauk U flotilla learned of its army's destruction, it turned back without engaging. Inside the walls, starvation set in. Defenders deserted in great numbers. On May 19, 1542, Minkhaung surrendered. He and his queen Thiri Hponhtut were taken to Toungoo as captives. The kingdom that had survived sixty years by playing its neighbors against each other had finally run out of neighbors willing to play. Prome would revolt once more, between 1594 and 1608, during the collapse of the First Toungoo Empire, before King Anaukpetlun annexed it permanently in July 1608.