History of the world
Whether in prehistoric or historic times, people always needed to be near reliable sources of potable water. Settlements developed on river banks as early as 3000 BCE in Mesopotamia, on the banks of Egypt's Nile River, in the Indus River valley, and along China's rivers. As farming developed, grain agriculture became more sophisticated and prompted a division of labour to store food between growing seasons. Labour divisions led to the rise of a leisured upper class and the development of cities, which provided the foundation for civilization. The growing complexity of human societies necessitated systems of accounting and writing.
Cradle of civilization
The earliest signs of a process leading to sedentary culture can be seen in the Levant to as early as 12,000 BC, when the Natufian culture became sedentary; it evolved into an agricultural society by 10,000 BC. The importance of water to safeguard an abundant and stable food supply, due to favourable conditions for hunting, fishing and gathering resources including cereals, provided an initial "wide spectrum economy" that triggered the creation of permanent villages.