Bayinnaung Kyawhtin Nawrahta was king of the Toungoo Dynasty of Burma from 1550 to 1581. During his 31-year reign, which has been called the "greatest explosion of human energy ever seen in Burma", Bayinnaung assembled what was probably the largest empire in the history of Southeast Asia, which included much of modern-day Myanmar, the Chinese Shan states, Lan Na, Lan Xang, Manipur and Siam.
Although he is best remembered for his empire building, Bayinnaung's greatest legacy was his integration of the Shan states into the Irrawaddy Valley-based kingdoms. After the conquest of the Shan states in 1557–1563, the king put in an administrative system that reduced the power of hereditary Shan saophas, and brought Shan customs in line with lowland norms. It eliminated the threat of Shan raids into Upper Burma, an overhanging concern since the late 13th century. His Shan policy was followed by Burmese kings right up to the final fall of the kingdom to the British in 1885.
Bayinnaung could not replicate this administrative policy everywhere in his far-flung empire, however.