The Conquest of Two Rivers. Mesopotamia, or the country between two rivers, is the oldest civilisation to have flourished at the confluence of two rivers: the Tigris and the Euphrates. The Mesopotamians included various peoples, the Sumerians, the Babylonians, the Akkadians, who coexisted and succeeded one another, mixing and inter-relating in a Near East with a wide range of racial facets. These different peoples, who once lived along the banks of the two rivers, have left behind an archaeological heritage of inestimable value. How did they flourish in such a hostile environment? Where did their wealth come from? And how did this perfectly structured civilisation finally fade and disappear for ever?