In politics and in history, a colony is a territory under the immediate political control of a geographically-distant state. For colonies in antiquity, city-states would often found their own colonies. Some colonies were historically separate countries, while others were territories without definite statehood at the moment of colonization. The metropolitan state is the state that owns the colony. In Ancient Greece, the city that owned a colony was called the metropolis within its political organization. Mother country is the term used to refer to the metropolitan state by its citizens that live in a colony. Today, the terms overseas territory or dependent territory are preferred. There is a United Nations list of Non-Self-Governing Territories.

People who migrated to settle permanently in colonies controlled by their country of origin were called colonists or settlers.

A colony differs from a puppet state or satellite state in that a colony has no independent international representation and the top-level administration of a colony is under direct control of the metropolitan state.

The term "informal colony" is used by some historians to describe a country which is under the de facto control of another state, although this description is often contentious. 
 
 
 
Definitions
 
In the modern usage, colony is generally distinguished from overseas possession. In the former case, the local population, or at least the part of it not coming from the "metropolitan" (controlling) country, does not enjoy full citizenship rights. The political process is generally restricted, especially excluding questions of independence. In this case, there are settlers from a dominating foreign country, or countries, and often the property of indigenous peoples is seized, to provide the settlers with land. Foreign mores, religions and/or legal systems are imposed. In some cases, the local population is held for unfree labour, is submitted to brutal force, or even to policies of genocide.

By contrast, in the case of overseas possessions, citizens are formally equal, regardless of origin and it is possible for legal independence movements to form; should they gain a majority in the overseas possession, the question of independence may be brought, for instance, to referendum. However, in some cases, settlers have come to outnumber indigenous people in overseas possessions, and it is possible for colonies to become overseas possessions, against the wishes of indigenous peoples. This often results in ongoing and long-lasting independence struggles by the descendants of the original inhabitants. In the context of this book series: Gibraltar.

Colonization at the end of World War II (1945)

Originally, as with the ancient (Hellenic) Greek apoikia, the term colonization referred to the foundation of a new city or settlement, more often than not with nonviolent means. The term colony is derived from the Latin colonia, which indicated a place meant for agricultural activities; these Roman colonies and others like them were in fact usually either conquered so as to be inhabited by these workers, or else established as a cheap way of securing conquests made for other reasons. The name of the German city Cologne also derives from colonia. In the modern era, communities founded by colonists or settlers became known as settler colonies.

The "age of imperialism" began in the 15th century with the initiation of the vast Portuguese and Spanish Empires in the Americas and lasted until the mid-20th century with the dismantling of the British Empire. During these centuries European states, the United States and others took political control of much of the world's population and landmass. The term "colony" came to mean an overseas district with a majority indigenous population, administered by a distant colonial government. (Exceptions occurred: Russian colonies in Central Asia and Siberia, American settlements in the American West, and German colonies in Eastern Europe were not "overseas"; British colonies (or "overseas territories") like the Falkland Islands and Tristan da Cunha lacked a native population.) Most non-European countries were colonies of Europe at one time or another, or were handled in a quasi-colonial manner. The European colonies and former colonies in America made extensive use of slave labor, initially using the native population, then through the importation of slaves from black Africa.

The Spanish colonial empire once encompassed all of South and Central America except for Brazil, with few exceptions; it crumbled starting in the early 19th century. After the Spanish and the Portuguese, the Dutch East India Company and later the Dutch West India Company took over a lot of Portuguese possessions and expanded their large trade empire. In the 19th century, the largest European colonial empire was the British Empire under Queen Victoria, including India. France once held much of Western and Central Africa, along with Indochina.

There existed various statuses and modes of operation for foreign countries, direct control by the colonizing country being the most obvious. Some colonies were operated through corporations (the British East India Company for India; the Congo Free State under the very brutal rule of Léopold II of Belgium); some were run as protectorates. Quasi-colonies were run through proxy or puppet governments, generally kingdoms or dictatorships (banana republic).

The United Kingdom used Australia as a penal colony: British convicts would be sent to forced labor there, with the added benefit that the freed convicts would settle in the colony and thus augment the European population there. Similarly, France once deported prostitutes and various "undesirables" to populate its colonies in North America, and until the 20th century operated a penitentiary on Devil's Island in French Guiana.

The independence of these colonies began with that of 13 colonies of Britain that formed the United States, with for example Algeria and East Timor being relinquished by European powers only in 1962 and 1975 respectively. This process is called decolonization, though the use of a single term obscures an important distinction between the process of the settler population breaking its links with the mother country while maintaining local political supremacy and that of the indigenous population reasserting themselves (possibly through the expulsion of the settler population).

Under the Geneva Conventions of 1949, it is a war crime to transfer, directly or indirectly, the civilian population of a country power onto land under that country's military occupation. The reasoning for this crime is apparently to emphasise that it is now a violation of international law to annex territory through military force. This phrase describes many of acts of colonisation in the past, and arguably outlaws colonisation.

Gibraltar has been a colonial possession of the British since 1713.