Answer:
The Sumerians were the civilization that existed approx. between 3,800 BCE and 2,000 BCE in the region delimited between the Tigris and Euphrates rivers (now Iraq). This was the first civilization that records our history and was, in many respects, the most powerful and developed among the many that followed.
Their records tell us about material, artistic, social, scientific and productive achievements, absolutely disruptive, which denote a true quantum leap with respect to the previous stage of history, rather than gradual progress.
The Sumerian civilization reached a level of superlative development, whose legacy reaches to this day. His knowledge, principles and beliefs were transmitted to the Akkadians, Babylonians, Assyrians, Hittites, and through them, to the Hebrew and Hellenic world, immediate precursors of ours.