Mesopotamia was firmly under the Sumerian people's control by 3000 BC. Eridu, Nippur, Lagash, Uruk, Kish, and Ur were among the decentralised city-states of Sumer. Uruk, which is about 30 kilometres east of the modern city of Samawah in Iraq, was Sumer's most important city. It was one of the first cities in the region, and it played a key role in Mesopotamia's urbanisation and state formation during the Uruk period. Uruk's expansion made it the most populous and largest Mesopotamian settlement in terms of both population and area. At its peak, around 2900 BC, it had a population of 40,000 to 80,000 people living in a 6 km2 walled area. As a result, Uruk was most likely the world's largest ci