About 10,000 years, some human beings gave up the nomadic life of hunting and gathering that had sustained humanity since the species first evolved. Instead, they settled in farming villages, domesticating animals and growing crops. This important change is sometimes called the "Neolithic revolution". Farming could support a larger population than hunting and gathering, so the size of human societies slowly began to increase. Eventually cities emerged, with inhabitants who specialized in different activities - for example, priests, merchants, and craftsmen. In the cities of Sumer in southern Mesopotamia and in the Indus valley in what is now Pakistan, people invented elaborate accounting systems and early forms of writing to facilitate trade and government. ≈@Mohenjo Daro@
Situated in the Indus valley in present-day Pakistan, Mohenjo-Daro was one of the first large cities of antiquity. In the heart of the city stood a fortified citadel that dominated the lower city. This fortification housed many large buildings, including the public pool and a granary. The lower city was home to workers and craftsmen and was built on a grid pattern. Houses were built of fired bricks. Most of them had a form of underground plumbing, a room with a well, and a bathroom.
