The Toungoo–Hanthawaddy War (1534–1541) (Burmese: တောင်ငူ–ဟံသာဝတီ စစ် (၁၅၃၄–၁၅၄၁)) was a military conflict between the Toungoo Kingdom, and the Hanthawaddy Kingdom and its allies the Prome Kingdom and the Confederation of Shan States that took place in present-day Lower Burma (Myanmar) between 1534 and 1541. In a series of improbable events, the upstart Burmese-speaking kingdom defeated the Mon-speaking Hanthawaddy, the most prosperous and powerful of all post-Pagan kingdoms before the war. In the following years, Toungoo used the newly acquired kingdom's wealth and manpower to reunify the various petty states that had existed since the fall of Pagan Empire in 1287.