In 1285, Narathihapate fled Pagan (Bagan) to Lower Burma in panic as the Mongol invasion advanced. In 1287, Thihathu, Viceroy of Prome (Pyay), 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.