When and why did the Sumerian writing emerge?

Sumerian writing arose at the beginning of the 4th millennium BC as a result of the birth of the first ancient civilization here. Mesopotamia was then a fairly developed region, where agriculture, handicrafts developed and cities were built. It is in such conditions that writing emerges. Sumerian writing is most often referred to as a pictogram. In those ancient times, the Sumerians wrote on clay tablets, on which symbols were carved with sticks. Then the board was placed in the sun and it dried up, which allowed it to be stored for a long time.