The Sumerians were one of the earliest known civilizations, emerging in the southern part of Mesopotamia around 4500 BCE. They are credited with many innovations, including the development of one of the first writing systems, known as cuneiform, which allowed them to record their history and transactions. Sumerian society was highly organized, with city-states like Ur and Lagash that featured advanced architecture, such as ziggurats. Their contributions to mathematics, astronomy, and law laid the groundwork for future civilizations, making them a pivotal part of human history.