Sumer is the earliest known civilization in the historical region of southern [[Mesopotamia]] (now southern Iraq), emerging during the Chalcolithic and early [[Bronze Age]] between the sixth and fifth millennium BC. It is also one of the first civilizations in the world, along with Ancient [[Egypt]], Norte Chico, [[Greek|Minoan]] civilization, Ancient [[China]], [[Mesoamerica]] and the [[Harappan]] civilization of the Indus Valley. Living along the valleys of the Tigris and Euphrates, Sumerian farmers grew an abundance of grain and other crops, the surplus from which enabled them to form urban settlements. Prehistoric proto-writing dates back before 3000 BC. The earliest texts come from the cities of Uruk and Jemdet Nasr, and date to between c. 3500 and c. 3000 BC. --- **Sumer:** By the fourth millennium BCE, Sumerians had established roughly a dozen city-states throughout ancient Mesopotamia, including Eridu and Uruk in what is now southern Iraq. Sumerians called themselves the Sag-giga, the “black-headed ones.” They were among the first to use bronze. They also pioneered the use of levees and canals for irrigation. Sumerians invented cuneiform script, one of the earliest forms of writing, and built large stepped pyramid temples called ziggurats. Sumerians celebrated art and literature. The 3,000-line poem “Epic of Gilgamesh” follows the adventures of a Sumerian king as he battles a forest monster and quests after the secrets of eternal life.