Mesopotamia, the ancient name for the land that is now Iraq, flourished as what was recognizably the same civilization for almost three thousand years, from 3200 BCE, when the people of the region invented a system of writing and the first cities arose, to 330 bce, when the Persian Achaemenid empire was conquered by the Greeks. Throughout those centuries, the people of Mesopotamia used the same writing system, worshiped the same gods, lived in the same cities, and traded the same types of goods. Mesopotamia was where some of the most important innovations in human history occurred first: cities, the wheel, the plow, written law, irrigation agriculture, mathematics, and imperial government. Although peoples elsewhere in the world developed many of these innovations at other times, Mesopotamia left an impressive legacy for the histories of Europe and Western Asia.
Mesopotamia was also a center for trade and for contact between cultures. Artifacts from prehistoric sites reflect the fact that long-distance trade was taking place long before anyone could record the transactions. Throughout the history of Mesopotamia, its people interacted vigorously with their neighbors, warring, trading, migrating, and sharing ideas.
Mesopotamia had many names during the height of its civilization, but Mesopotamia was not one of them. It was the ancient Greeks who named the valley of the Euphrates and Tigris Rivers “the land between the rivers” (meso = between, potamia = rivers), and the name has stuck. In the third and early second millennia BCE, there was no name for the region as a whole. The southernmost part, the area closest to the Persian Gulf, was called Sumer. Slightly to the north of Sumer, where the Tigris and Euphrates flow closest together, was the land of Akkad. Later, when these two lands were united under a single government, they came to be thought of as one state, which we call Babylonia. North of Babylonia on the Tigris was a land that had a deep historic connection with Babylonia. It was called Ashur, or Assyria, in our modern terminology. But rarely during ancient history was the land of Mesopotamia a political whole.