Another group, the
Mranma (Burmans or Bamar) of the
Nanzhao Kingdom, entered the upper Irrawaddy valley in the early 9th century. They went on to establish the
Pagan Empire (1044–1287), the first ever unification of Irrawaddy valley and its periphery. The
Burmese language and
culture slowly came to replace Pyu and Mon norms during this period. After
Pagan's fall in 1287, several small kingdoms, of which
Ava,
Hanthawaddy,
Arakan and
Shan states were principal powers, came to dominate the landscape, replete with ever shifting alliances and constant wars.
In the second half of the 16th century, the
Toungoo Dynasty (1510–1752) reunified the country, and founded the largest empire in the history of Southeast Asia for a brief period. Later Toungoo kings instituted several key administrative and economic reforms that gave rise to a smaller, peaceful and prosperous kingdom in the 17th and early 18th centuries. In the second half of the 18th century, the
Konbaung Dynasty (1752–1885) restored the kingdom, and continued the Toungoo reforms that increased central rule in peripheral regions and produced one of the most literate states in Asia. The dynasty also went to war with all its neighbors. The kingdom
fell to the British over a six-decade span (1824–85).
The
British rule brought several enduring social, economic, cultural and administrative changes that completely transformed the once-agrarian society. Most importantly, the British rule highlighted out-group differences among the country's myriad ethnic groups. Since independence in 1948, the country has been in
one of the longest running civil wars that remains unresolved. The country was under military rule under various guises from 1962 to 2010, and in the process has become one of the least developed nations in the world.