Sumer
Sumer () is the earliest known civilization in the historical region of southern Mesopotamia, modern-day southern Iraq, during the Chalcolithic and Early Bronze ages, and one of the first civilizations in the world along with Ancient Egypt and the Indus Valley. Living along the valleys of the Tigris and Euphrates, Sumerian farmers were able to grow an abundance of grain and other crops, the surplus of which enabled them to settle in one place. Prehistoric proto-writing dates back before 3000 BC. The earliest texts, from c. 3300 BC, come from the cities of Uruk and Jemdet Nasr; early cuneiform script emerged around 3000 BC.
Iraqis
In ancient and medieval times Mesopotamia was the political and cultural centre of many great empires, such as the Akkadian Empire, Assyria, and Babylonia. The ancient Mesopotamian civilization of Sumer is the oldest known civilization in the world, and thus Iraq is widely known as the cradle of civilization. Iraq remained an important centre of civilization for millennia, up until the Abbasid Caliphate (of which Baghdad was the capital), which was the most advanced empire of the medieval world (see Islamic Golden Age).