In late 1538, Toungoo again opened its annual dry season campaign.
It would have been like any previous one except that in a series of improbable events, Toungoo went on to conquer Lower Burma (except Martaban) in a blitz.
By using a stratagem, Toungoo armies took Pegu without firing a shot.
A few weeks later, Hanthawaddy's larger but poorly-led forces were decisively defeated at the Battle of Naungyo by light forces of Gen. Kyawhtin Nawrahta (Bayinnaung).
Only a weakened Hanthawaddy force made it to Prome.

The rapid turn of events caught everyone by surprise.
Narapati immediately asked Ava for help.
While a flatfooted Thohanbwa scrambled to round up the troops, about 7000 Toungoo land and naval forces converged on Prome, the gateway to central Burma.
But the city's fortified defenses held out long enough.
Finally, 5000 Ava troops arrived in 300 war boats to break up the siege, and chased Toungoo forces back to the delta.
The Confederation's advance was halted at Inbyaw Island (အင်းပြောကျွန်း) where six Confederation commanders, including Gen. Nawrahta of Kanni, were captured in a naval battle.

It turned out to be the last battle of the season.
Despite Takayutpi's repeated urges to push on, his allies decided not to proceed any further.
A deeply frustrated Takayutpi died soon after while trying to catch wild elephants for his army.
Narapati too died shortly after from dysentery.
In late 1538, Toungoo again opened its annual dry season campaign. It would have been like any previous one except that in a series of improbable events, Toungoo went on to conquer Lower Burma (except Martaban) in a blitz. By using a stratagem, Toungoo armies took Pegu without firing a shot. A few weeks later, Hanthawaddy's larger but poorly-led forces were decisively defeated at the Battle of Naungyo by light forces of Gen. Kyawhtin Nawrahta (Bayinnaung). Only a weakened Hanthawaddy force made it to Prome.
The rapid turn of events caught everyone by surprise. Narapati immediately asked Ava for help. While a flatfooted Thohanbwa scrambled to round up the troops, about 7000 Toungoo land and naval forces converged on Prome, the gateway to central Burma. But the city's fortified defenses held out long enough. Finally, 5000 Ava troops arrived in 300 war boats to break up the siege, and chased Toungoo forces back to the delta. The Confederation's advance was halted at Inbyaw Island (အင်းပြောကျွန်း) where six Confederation commanders, including Gen. Nawrahta of Kanni, were captured in a naval battle.
It turned out to be the last battle of the season. Despite Takayutpi's repeated urges to push on, his allies decided not to proceed any further. A deeply frustrated Takayutpi died soon after while trying to catch wild elephants for his army. Narapati too died shortly after from dysentery.
Toungoo–Ava War (1538–1545)