The Ancient Sumerian city-states in the Mesopotamian region of the Middle East fought with each other for control of the irrigated land needed to grow their crops. Located between the Tigris and Euphrates Rivers, the Mesopotamian region would have remained dry and unsuited for agriculture if not for the yearly replenishment of fertile land brought about by the flooding of these two rivers. Control of the water, one of the most valuable resources in the area, determined which city-state would be able to grow enough crops to feed its inhabitants.
The Sumerian city-states encompassed a relatively small area believed to have been about the size of Northern Ireland. Some of the city-states were in sight of each other and included a surrounding area of towns, agricultural fields and irrigation works. There were few natural boundaries between city-states and their close proximity to each other, and competition for water and fertile land often led to wars fought over the availability of those two essential resources.