He seized up to Yamethin in 1428–29, and in an alliance with King Binnya Ran I of Hanthawaddy Pegu attempted to pick off Prome (Pyay) in 1430–31.
[2][3] The king had been looking for a loyal and able governor for the restive region bordering the Hanthawaddy Kingdom (Pegu) with which Ava had been in a long drawn out war since 1385.
That year, Queen Shin Bo-Me engineered the assassinations of kings Thihathu and Min Hla within three months of each other, and placed her lover Gov.
[4] But when the tide of war turned in favor of Mohnyin, Thinkhaya and other rulers retreated to their respective regions, taking their troops back with them.
When Thado ordered the southern vassal rulers to Ava, he reluctantly went there, bringing a small retinue led by Myat Hla.
Rulers of Toungoo, Taungdwin, Thissein, Yenantha, Pinle and Onbaung all revolted soon after they got back to their home region.
[7][8] According to the chronicle Toungoo Yazawin, Thinkhaya sent a formal letter to Thado, addressing the latter as "younger brother", and declaring is independence from Ava as well as his preparedness to go to war, if necessary.
In 1428–29, he annexed the five irrigated zones of the Yamethin region immediately to Toungoo's north, and even raided the districts towards the Irrawaddy such as Natmauk and Kyaukpadaung.
[9] He next entered into a formal alliance with Pegu by sending his younger daughter Saw Min Aung to Binnya Ran in a marriage of state.
[11] (In response, Thado appointed his son Thihathu governor of Prome, replacing loyal but old Min Maha, in 1429.
[9] Given troubles closer to home, Ava was unwilling to fight a drawn out war in the south, and reluctantly asked for terms.
Thado also sent Princess Soe Min Wimala Dewi to Pegu to wed Ran in a marriage of state.
According to Toungoo Yazawin, when he built a new palace, he refused to install the white umbrella (Hti byu), a key part of the regalia of Burmese sovereigns, perhaps not to attract unwanted attention.