Early civilizations started along rivers for many reasons, including access to water, fertile land, and areas that could easily be protected. Once people established permanent settlements, they began to invent new items like written language, clay pottery, and more modern agricultural practices. They also established a government and religious practices, and created stories to remember and explain their cultural and everyday occurrences.

Sumer of Mesopotamia was the first civilization, and the leader and people who settled there created one of the first written law codes, the Code of Hammurabi. The populations throughout Mesopotamia were polytheistic, and due to the unpredictable nature of the weather in this region of the world, ancient people perceived these gods as in control of the environment.