Among the several factors responsible for the rise of principalities and kingdoms in early Southeast Asia, agriculture and maritime trade must be deemed the most important. Clusters of population and political power arose where agricultural surpluses, contributing to trade, could be built up. The vagaries of the monsoons and the physical characteristics of the land provided a challenge to people’s ingenuity and skill in organizing water control and soil conservation. Where this was achieved, agriculture prospered, as in the silt-rich deltas in mainland Southeast Asia, the plains of central Myanmar, the region around Tonle Sap Lake in Cambodia, and the central and eastern parts of Java. The relationship between agricultural prosperity and the rise of states in these areas is obvious. On the other hand, certain principalities, whose main source of revenue was trade, sprang up in relatively infertile areas of southeastern Sumatra and coastal Malaya. Their asset was their location on the India-China trade route. Among the many locations where early states emerged, the greatest advantage accrued to the delta regions of Southeast Asia, where a combination of fertile soil and proximity to the sea helped both agriculture and commerce.