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.
Prehistory
Sumer in Mesopotamia, the Indus valley civilization and ancient Egypt were the first civilizations to develop their own scripts, and to keep historical records; this took place already during the early Bronze Age. Neighboring civilizations were the first to follow. Most other civilizations reached the end of prehistory during the Iron Age. The three-age system of division of prehistory into the Stone Age, followed by the Bronze Age and Iron Age, remains in use for much of Eurasia and North Africa, but is not generally used in those parts of the world where the working of hard metals arrived abruptly with contact with Eurasian cultures, such as the Americas, Oceania, Australasia and much of Sub-Saharan Africa. These areas also, with some exceptions in Pre-Columbian civilizations in the Americas, did not develop complex writing systems before the arrival of Eurasians, and their prehistory reaches into relatively recent periods; for example 1788 is usually taken as the end of the prehistory of Australia.