" The archaeological landscape of Upper Burma from the middle of the first millennium BC to the Bagan period in the 13th-14th century AD is a landscape of continuity. Finds of polished stone and bronze artifacts suggest the existence of early metal-using cultures in the Chindwin and Samon River Valleys, and along parts of the Ayeyarwady plain. Increasing technological and settlement complexity in the Samon Valley suggests that a distinctive culture whose agricultural and trade success can be read in the archaeological record of the Late Prehistoric period developed there. The appearance of the early urban ?Pyu” system of walled central places during the early first millennium AD seems to have involved a spread of agricultural and management skills and population from the Samon. The leaders of the urban centres adopted Indic symbols and Sanskrit modes of kingship to enhance and extend their authority. The early urban system was subject over time to a range of stresses including siltation of water systems, external disruption and social changes as Buddhist notions of leadership eclipsed Brahmanical ones. The archaeological evidence indicates that a settlement was forming at Bagan during the last centuries of the first millennium AD. By the mid 11th century Bagan began to dominate Upper Burma, and the region began a transition from a system of largely autonomous city states to a centralised kingdom. Inscriptions of the 11th to 13th centuries indicate that as the Bagan Empire expanded it subsumed the agricultural lands that had been developed by the Pyu."