sumerian civilization

How did the Sumerian Empire arise and fall?
The Sumerian civilization was the earliest civilization in human history. The location of the Sumerian civilization was Mesopotamia, between the Tigris and Euphrates rivers, from
The latest revelation about a civilization of more than 6000 years that history books are also 'terrible' not daring to mention
The mysterious civilization has shocked and influenced the world until now, but it is not mentioned in history books because of its 'terrible'.