Pyu city-states
Beikthano ( ) situated in the irrigated Minbu region (near present-day Taungdwingyi) with direct land access to the well-watered Kyaukse plains to its northeast, is the oldest urban site so far discovered and scientifically excavated site. Its remains—the structures, pottery, artefacts, and human skeletons—date from 200 BCE to 100 CE. Named after the Hindu god Vishnu, the city may be the first capital of a culturally and perhaps even politically uniform state in the history of Burma. It was a large fortified settlement, measuring approximately 300 hectares inside the rectangular (3 km by 1 km) walls. The walls and fortifications along it measured six meters thick, and are radiocarbon dated to a period between 180 BCE and 610 CE. Like most subsequent cities, the main entrance of the walls led to the palace, which faced east. Stupas and monastic buildings have also been excavated within the city walls.
History of Myanmar
According to the colonial era scholarship, as early as the 6th century, another people called the Mon began to enter the present-day Lower Burma from the Mon kingdoms of Haribhunjaya and Dvaravati in modern-day Thailand. By the mid 9th century, the Mon had founded at least two small kingdoms (or large city-states) centred around Bago and Thaton. The earliest external reference to a Mon kingdom in Lower Burma was in 844–848 by Arab geographers. But recent research shows that there is no evidence (archaeological or otherwise) to support colonial period conjectures that a Mon-speaking polity existed in Lower Burma until the late 13th century, and the first recorded claim that the kingdom of Thaton existed came only in 1479.