Proto-civilisation is the transitional state between a society structured as a collection of tribal chieftains, perhaps owing allegiance to a paramount chief, and the development of a full urban civilisation, in which people live in a graded hierarchy of settlement types perhaps starting with isolated peasant farms, hamlets or small villages, through market towns, to centralised capital cities or ceremonial centres. It is an important stage in the genesis of a civilisation, but historically appears to be an unstable threshold, often reverting back to tribal or chieftain cultures if unable to "progress" to a full blown and semi-stable civilisation.

Examples of proto-civilisations are found preceding the development of almost all civilisations, but there are also examples of many proto-civilisations that failed to generate a separate civilisation. For example the La Tene Celt

Celt

The Celts were a diverse group of tribal societies in Iron Age and Roman-era Europe who spoke Celtic languages.The earliest archaeological culture commonly accepted as Celtic, or rather Proto-Celtic, was the central European Hallstatt culture , named for the rich grave finds in Hallstatt, Austria....

ic culture of oppida, stretching from such sites as at Hueneburg in Southern Germany, to the Belgae

Belgae

The Belgae were a group of tribes living in northern Gaul, on the west bank of the Rhine, in the 3rd century BC, and later also in Britain, and possibly even Ireland...

 kingdoms of Southern Britain, show many of the characteristics of a proto-civilisation; including the settlement hierarchy already mentioned, the development of an upper "princely" class having a monopoly on institutionalised violence, the development of specialised functionaries, artisans and craftspeople. It is quite possible that this development would have led to a fully Celtic civilisation, if the areas had not been conquered by the Romans and included as the western part of the Roman Empire

Roman Empire

The Roman Empire was the post-Republican period of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean....

. The proto-civilization sites have achieved much and made a big impact on today's society.
In North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

, the Mississippian culture

Mississippian culture

The Mississippian culture was a mound-building Native American culture that flourished in what is now the Midwestern, Eastern, and Southeastern United States from approximately 800 CE to 1500 CE, varying regionally....

 is believed to have produced proto-civilizations at such sites as Cahokia

Cahokia

Cahokia Mounds State Historic Site is the area of an ancient indigenous city located in the American Bottom floodplain, between East Saint Louis and Collinsville in south-western Illinois, across the Mississippi River from St. Louis, Missouri. The site included 120 human-built earthwork mounds...

 in Illinois

Illinois

Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...

, Moundville

Moundville Archaeological Site

Moundville Archaeological Site, also known as the Moundville Archaeological Park, is a Mississippian site on the Black Warrior River in Hale County, near the town of Tuscaloosa, Alabama...

 in Alabama

Alabama

Alabama is a state located in the southeastern region of the United States. It is bordered by Tennessee to the north, Georgia to the east, Florida and the Gulf of Mexico to the south, and Mississippi to the west. Alabama ranks 30th in total land area and ranks second in the size of its inland...

, and Etowah

Etowah Indian Mounds

Etowah Indian Mounds is a archaeological site in Bartow County, Georgia south of Cartersville, in the United States. Built and occupied in three phases, from 1000–1550 CE, the prehistoric site is located on the north shore of the Etowah River. Etowah Indian Mounds Historic Site is a designated...

 in Georgia

Georgia (U.S. state)

Georgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...

.