Byat Za's Martaban campaign was from 1389-1390, when they co-cammanded the army and navy with Dein that took the Irrawaddy delta.
It came at the end of the Irrawaddy delta campaign of 13891390. For their part, Byat Za and Dein dutifully carried out their responsibilities even if they did not agree with the king's decision. After Pegu defenses had successfully held off repeated Ava land and naval attacks, the Pegu court persuaded their king to return Gu-Htut to Ava in exchange for Ava's recognition. 
