The earliest cities developed within a broad transformation of human society called the “urban revolution.” Simpler agricultural societies grew into complex, urban states independently in at least six parts of the world. The first large-scale complex societies, often referred to as “pristine states,” developed in Mesopotamia, Egypt, the Indus Valley, North China, the Andes, and Mesoamerica. This entry covers ancient cities starting with the pristine states and ending prior to the Classical period in the Mediterranean and prior to European conquest in other parts of the world.