In the reign of Anawratha (1044-1077), the Burmese have extended their influence over Myanmar today. Until the 1100s, the large areas of mainland Southeast Asia was under the control of the Pagan kingdom, with the capital in Mandalay.
According to the oral history of the Burmese and Mon, Mon had ever been a wealthy nation and civilization in the Ayeyarwady Delta - Thaton kingdom. But Pagan Anawratha king invaded and annexed Mon kingdom. However, we have not found any archaeological objects convinced the existence of the nation. Perhaps the archaeological research is conducted primarily in upper Myanmar. Maybe, the pressure of the Khmer Empire, the Mon from the Dvaravati (now in central Thailand) evacuated to lower Myanmar around the 9th century.
For over 200 years, until the late 13th century, Pagan Empire flourished, largely controlled territory Myanmar today. This is a Buddhist kingdom that the remaining temples in Bagan today demonstrate not only the culmination of wealth in agriculture, but also to prove people's wisdom of mathematics, geometry, and construction. The temples of Bagan stretch 40 square km area on the waterfront of Ayeyarwady. Pagan is golden age from 11-13 century in the minds of Burmese people.