Thihathu was born to Queen Shin Mauk and Narathihapate in the late 1250s in Pagan (Bagan). Thihathu grew up at the palace alongside his half-brothers Uzana and Kyawswa, and appeared to have been the black sheep of the family. According to the royal chronicles, the king constantly teased Thihathu in front of others, for which Thihathu nursed malice toward his father.
He was the maternal grandfather of King Swasawke of Ava. Nonetheless, in 1275, he was appointed viceroy of Prome (Pyay), which was reestablished at the old city of Thray Khittaya (Sri Ksetra). His chance for payback came during the Mongol invasion of the country in 1283-1285.
En route at Prome, on 1 July 1287, Thihathu arrested his father and forced the king to take poison.
To refuse would have meant death by the sword, and with a prayer on his lips that in all his future existences "may no male-child be ever born to him again", the king swallowed the poison and died. Having killed the king, Thihathu next tried to kill off his two rival half-brothers, Uzana (Governor of Pathein) and Kyawswa (Governor of Dala) as they were also potential claimants to the throne.
Thihathu first went to Pathein, entered Uzana"s chambers, and hacked Uzana, who laid sick in his chamber, to pieces. He then sailed to Dala to kill Kyawswa.
Kyawswa had fortified Dala, and withstood Thihathu"s several charges to take the port city.
Thihathu then went northeast of Dala to Pegu whose ruler had also fortified the city. At the Pegu harbor, as he tried to shoot one of the guards with his crossbow, he accidentally killed himself by his own arrow. They had at least one daughter, Shin Myat Hla, the mother of King Swasawke of Ava.
