The first known civilization in Mesopotamia is Sumer. This ancient civilization emerged around 4500 BCE in the southern region of Mesopotamia, present-day southern Iraq. Sumer is notable for its innovations, including the development of one of the earliest writing systems, cuneiform, as well as significant advancements in agriculture, art, and architecture. The Sumerians built city-states, such as Ur and Uruk, and created complex societal structures with governance, religion, and trade networks. Their contributions set the foundation for subsequent civilizations in the region, making Sumer a crucial chapter in the history of human development.