Cucuteni–Trypillia culture in the context of "Histria (ancient city)"

The Chalcolithic or Copper Age is the transitional period between the Neolithic and the Bronze Age. It is taken to begin around the mid-5th millennium BC, and ends with the beginning of the Bronze Age proper, in the late 4th to 3rd millennium BC, depending on the region.

The Chalcolithic is part of prehistory, but based on archaeological evidence, the emergence of the first state societies can be inferred, notably in the Fertile Crescent (notably Sumer) Predynastic Egypt, and Proto-Minoan Crete, with late Neolithic societies of comparable complexity emerging in the Indus Valley (Mehrgarh), China, and along the north-western shores of the Black Sea.

A proto-city is a large, dense Neolithic settlement that is largely distinguished from a city by its lack of planning and centralized rule. The term mega-sites is also used. While the precise classification of many sites considered proto-cities is ambiguous and subject to considerable debate, common examples include sites of the Pre-Pottery Neolithic B culture and following cultures in the Fertile Crescent such as Jericho and Çatalhöyük, sites of the Cucuteni-Trypillia culture in Southeast Europe, and of the Ubaid period in Mesopotamia. These sites pre-date the Mesopotamian city-states of the Uruk period that mark the development of the first indisputable urban settlements, with the emergence of cities such as Uruk at the end of the Fourth Millennium, B.C.

The emergence of cities from proto-urban settlements is a non-linear development that demonstrates the varied experiences of early urbanization. Whilst the proto-urban sites of the Ubaid period in northern Mesopotamia anticipate the social and political developments of the first Sumerian cities, many proto-cities show little correlation with later urban settlements. The development of cities and proto-cities and the transition away from hunting and gathering toward agriculture is known as the Neolithic Revolution.