Byattaba
Nyi San apparently was in sufficiently high social standing that he was given the title Byattaba, and was allowed to marry Princess Tala Mi Ma-Hsan, daughter of Saw Zein and half-sister of Binnya U (r.
By the early 1360s, he had brought the two elder brothers—Byattaba and E Bya Bon—into his inner circle, and appointed the third brother Laukpya governor of Myaungmya, a key port in the Irrawaddy Delta.
The main instigator was Laukpya, who was posted far away from Martaban, and had quickly developed a network of support across the delta province through a series of alliances.
The king believed that his victory over the Lan Na invasion of 1351–1352 was due to the luck brought by his white elephant.
[5] The king and his sizable retinue, consisted of his key advisers, generals and 2000 troops, went on the planned hunting trip, c. November 1363.
The king left the capital in the trusted hands of Byattaba, who in turn was aided by his brothers E Bya Bon and U-Lo.
[3] Only their half-brother Lagun, governor of a small eastern delta town of Let-Hlyit remained loyal to the king.
His troops recaptured Lagun Byi from E Bya Bon but twice failed to take Martaban, losing his two best generals in the process.
They appealed to the king of Lan Na to intervene, promising a cut of the tax revenue of Martaban and Moulmein ports.
During the mourning period, E Bya Bon and 700 warriors, disguised as mourners, managed to get inside Donwun, and seized U's palace.
The king fled to Pegu (Bago), about 120 km northwest of Donwun, across the Bay of Martaban, and relocated his capital there.
[13] The traditional home of the dynasty, Martaban, on the other hand, was located on the upper Tenasserim coast, and too close to the Tai kingdoms to the east.
[15] Meanwhile, U secured his rear by successfully negotiating a peace treaty with King Swa Saw Ke of Ava that demarcated the border between the two kingdoms.
His daughter Tala Mi Thiri was never happy at Chiang Mai, and had been asking her father to bring her back for several years.
The two sides then agreed to a treaty that called for U to recognize the brothers as the rightful viceroys of Martaban and Bassein (Irrawaddy delta) provinces, and to pay them 10 viss (16.33 kg) of gold and ten elephants in exchange for the brothers' recognition of U as their sovereign as well as brokering of an agreement with Lan Na to maintain peace.
[note 5] As the Razadarit Ayedawbon recounts, U realized the absurdity of the overlord paying tribute to the vassals but he ultimately decided to swallow his pride, and agreed to the terms.
[19] On the other hand, Byattaba and Laukpya realized that they needed Lan Na's support in order to neutralize Pegu's stronger position.
For their part, they did not get involved in the affairs of Pegu even when the king gradually withdrew from governing due to his long illness.
When princess-regent Maha Dewi asked them to contribute troops to put down the rebellion, each sent a regiment to ensure that the fighting would not spill over to their territories.
[25][26] Byattaba, whose territory bordered the Tai states to the east, was much more circumspect about an alliance with Ava, and ultimately decided to stay neutral.
In 1387, after two failed invasions, Ava had to pause its war in the south as it was pulled into a renewed conflict with the northern Shan state of Maw.
But the Martaban command did not know that two Pegu rearguard regiments, led by generals Smim Than-Byat and Dein, were still in the area.
[31][32] At Martaban, a victorious Razadarit had Byattaba's chief wife Princess Tala Mi Ma-Hsan present all the tax payments owed to his father Binnya U in gold, silver, pearls, emeralds, and other precious stones.
[3] The couple had one daughter named Tala Thazin Zaw-Ngaik, who was married to her first cousin Saw E Binnya, son of Laukpya.
