Repeated Mongol invasions (1277–1301) toppled the four-century-old kingdom in 1287.Pagan's collapse was followed by 250 years of political fragmentation that lasted well into the 16th century.
The Bronze Age arrived circa 1500 BC when people in the region were turning copper into bronze, growing rice and domesticating poultry and pigs; they were among the first people in the world to do so.
Iron Age Burmese cultures also had influences from outside sources such as India and Thailand, as seen in their funerary practices concerning child burials.
Pagan gradually grew to absorb its surrounding states until the 1050s–1060s when Anawrahta founded the Pagan Kingdom, the first ever unification of the Irrawaddy valley and its periphery.
In the 12th and 13th centuries, the Pagan Empire and the Khmer Empire were two main powers in mainland Southeast Asia.
Theravada Buddhism slowly began to spread to the village level, although Tantric, Mahayana, Hinduism, and folk religion remained heavily entrenched.
Pagan's rulers and wealthy built over 10,000 Buddhist temples in the Pagan capital zone alone.
In the mid-to-late 9th century the Bamar people founded a small settlement at Bagan.
It was one of several competing city-states until the late 10th century when it grew in authority and grandeur.
This indicates some form of communication between groups in Myanmar and other places, possibly through trade.