The creation of a state and kingdom usually took place in the lowlands because settlement could be permanent and food production was sufficient to feed the whole population. Additionally, communication and technology could be developed more easily. Nevertheless, in the evolution of a lowland state, highlanders were also important, because lowlanders and highlanders exchanged products with each other. Highland products played a significant role in the economic prosperity of lowlanders until they were able to develop their nation state. Such an instance was reflected in the relationship between the Lua, Lawa and Karen ethnic groups and the Thai state. The ethnic groups had abundant natural resources needed by lowlanders. Therefore, archeological evidence has been found to indicate the relationships between the two groups.