The document discusses the Sumerian civilization that emerged around 3200 BC in the Fertile Crescent region between the Tigris and Euphrates Rivers in Mesopotamia. The Sumerians developed one of the earliest systems of writing called cuneiform using reed pens in wedge-shaped marks on clay tablets. They also made advances in mathematics, dividing time and circles into basic units still used today. Sumerian cities had distinct social hierarchies and believed in polytheistic religions where gods controlled nature and were worshipped in ziggurats.