The characteristic political organization of the tigris-euphrates civilization was

Regional city States was the characteristic political organization of the Tigris-Euphrates civilization.

Tigris and Euphrates are two rivers, and the region between them is known as Mesopotamia. In Ancient Greek, the word Mesopotamia means between the rivers. The civilization is known as Tigris-Euphrates Civilization. Sumerians and Akkadians are dominant there from the beginning.