Forty Years' War

Name of a military conflict fought from 1385 to 1424 AD between the Kingdom of Ava, ruled by King Minkhaung I, and the Kingdom of Hongsawadih controlled by King Razadarit, though interrupted by a truce twice. Initially, Ava invaded Hongsawadih multiple times but was defeated each time, after which a truce was agreed in 1391. In 1401 a new battle was initiated by Hongsawadih, when Hongsawadih  King Razadarit invaded Upper Burma in full force with a large flotilla, though when Ava's defenses held, another truce was agreed in 1403. However, when between 1404 and 1406 Ava went on an expansion spree, absorbing the Shan states Kale and Mohnyin in the north, and Arakan in the west, Hongsawadih could not allow Ava to get too strong and renewed the war in 1408 AD, with the Shan state of Hsenwi as an ally. Thus being forced to fight on on multiple fronts, Ava in 1414 successfully invaded Hongsawadih in full force and conquered the Irrawaddy River Delta in 1415 commanded by the Ava Crown Prince Minye Kyawswa. However, when the latter was killed in battle in March 1415, the enthusiasm for war dissipated on both sides and the subsequent campaigns were fought half-heartedly. After the deaths of King Razadarit in 1421 and King Minkhaung I in 1422, Ava's new monarch, King Thihathu and Pegu's Crown Prince Binnya Ran I made peace in 1424, a peace sealed by Crown Prince Binnya Ran I giving his elder sister Shin Sawbu to Thihathu and followed by Ava withdrawing its forces. Also referred to as Ava-Pegu War and Mon-Burmese War. 回