Answer:
Sumer civilization is the answer.
Explanation:
The Sumer Civilization arose in the mentioned area (along the Tigris and Euphrates Rivers) around 4,000 befor Christ. Niniveh was one of its main cities, located where we can find Iraq nowadays. Even though the origins of this civilization is not clear, many historians point out that they had stablished around ten to twelve cities by 4,000 B. C.
