At the coronation ceremony, Phalaung, who was styled as Sikandar Shah, the Sultan of Bengal, took Sekkya's daughter Saw Shin Latt (his first cousin, twice removed) as queen.
Its eastern policy had been to not to attract the attention of Toungoo Dynasty, which under King Bayinnaung was assembling the largest empire in the history of Southeast Asia.
In January 1575,[note 2] he sent a well-armed expeditionary force led by Crown Prince Thado Dhamma Raza to Tripura.
The Arakanese forces easily captured the Tripuri capital, after which Tripura agreed to pay tribute.
On 9 September 1580 (1st waxing of Thadingyut 942 ME), Toungoo army and naval forces (24,000 troops, 1200 horses, 120 elephants, 1300 boats) led by Thiri Thudhamma Yaza, son of Bayinnaung and governor of Martaban, quickly seized Thandwe (Sandoway).
[10] Unlike the previous invasion, Toungoo forces were prepared for the long haul, and laid siege to the city for over a year.
[8] After the war, he continued the policy of not interfering in the eastern affairs even when King Nanda, the successor of Bayinnaung, struggled mightily, and increasingly unsuccessfully, to keep the massive Toungoo Empire intact.
The governor had received aid from a northern state of Uttara Raj (ဥတ္တရာဇ်, Burmese pronunciation: [ʔoʊʔ tə ɹɪʔ]; lit.
After a brief stay at Chittagong, the army left for Uttara Raj (northern Bengal) on 24 December 1586 (full moon of Pyatho 948 ME).
According to the British historian Arthur Purves Phayre Phalaung realm probably stretched only to Noakhali, and Tripura.
[12] The king built a new palace, which he first entered with a lavish ceremony on 8 September 1577 (Sunday, 11th waning of Tawthalin 939 ME).
He led the relic chamber closing ceremony on 29 March 1592 (Sunday, 2nd waning of Late Tagu 953 ME).