Mingyi Nyo, now styled as Thiri Zeya Thura, eagerly assisted Ava in its fight against Yamethin. (His grandfather Sithu Kyawhtin died in 1481 fighting against the Yamethin rebels.) Even with Toungoo's help, the Yamethin rebellion was intractable and remained a stalemate. (It would remain so until Minye Kyawswa's death in August 1500). With Ava chiefly preoccupied by Yamethin, Nyo grew more confident and on 11 November 1491 built a new fortified city called Dwayawaddy (still near Toungoo), at the estuary of the rivers Kabaung and Paunglaung.