Forty Years' War

Forty Years' War
Date 1385–1423 Location Primarily in Lower Burma also in Upper Burma, Arakan, Shan States Result Stalemate Pegu preserves independence Arakan tributary of Pegu (1412–1421) Territorial changes No long-term changes
Belligerents
Ava Kale Mohnyin	Hanthawaddy Pegu Arakan Theinni
Commanders and leaders
Swa Saw Ke Tarabya Thilawa Minkhaung I Minye Kyawswa † Thihathu	Razadarit Byat Za Dein Mani-Yut Lagun Ein † Smin Bayan Binnya Ran I Min Saw Mon or Min Khayi

The Forty Years' War (Burmese: အနှစ်လေးဆယ်စစ်; 1385 – 1423; also Ava–Pegu War or the Mon–Burmese War) was a military war fought between the Burmese-speaking Kingdom of Ava and the Mon-speaking Kingdom of Hanthawaddy. The war was fought during two separate periods: 1385 to 1391, and 1401 to 1424, interrupted by two truces of 1391–1401 and 1403–1408. It was fought primarily in today's Lower Burma and also in Upper Burma, Shan State, and Rakhine State. It ended in a stalemate, preserving the independence of Hanthawaddy, and effectively ending Ava's efforts to rebuild the erstwhile Pagan Kingdom.