The first human settlements occurred around 10,000 B.C.E (12,000 years ago). Humans transitioned from primarily hunting and gathering communities to settlements in small pockets around the world. The core reason behind this transition was the development of domesticated plants and animals. Around 10,000 BCE, humans began to grow their own crops near rivers (Mesopotamia, China, India and Egypt) while also raising livestock for meat (Goats, Sheep, Pigs, Chicken, Cows). These early settlement were relatively small, and consisted mostly of a few families living, farming, and fishing together. The only records we have of these early settlements are archeological findings such as tools and bones dug up from the earth.
The first civilization, which is a much more complex society consisting of writing, hierarchy and social organization is considered to have developed in Mesopotamia ("The Land Between Two Rivers") in what is modern day Iraq and Iran. Mesopotamia is also called the "Fertile Crescent" and the "Cradle of Civilization" as they were the first society to take up agriculture on a large scale and see a rapid growth of population and urbanization relative to their contemporaries. The Mesopotamians are credited with creating the world's first writing system (cuneiform) as well as the world's first written legal system (Hammurabi's Code). The Mesopotamian civilization consisted of various "City-States" spread out over the region that were often in conflict with one another.