Colonialism is the policy of a country seeking to extend or retain its authority over other people or territories, generally with the aim of economic dominance. The colonising country seeks to benefit from the colonised country or land mass. In the process, colonisers may impose their religion, economics, and medicinal practices on the natives. Colonialism is the relationship of domination of indigenous by foreign invaders where the latter rule in pursuit of their interests.
Starting in the 15th century some European states established their own empires during the European colonial period. The Belgian, British, Danish, Dutch, French, Ottoman :116 Portuguese, Russian, Spanish and Swedish empires established colonies across large areas. Japan, the United States and China also followed this path, as did the Germans and the Italians in the late 19th century.
At first, European colonising countries followed policies of mercantilism, in order to strengthen the home economy, so agreements usually restricted the colonies to trading only with the metropole (mother country). By the mid-19th century, however, the British Empire gave up mercantilism and trade restrictions and adopted the principle of free trade, with few restrictions or tariffs. Christian missionaries were active in practically all of the European controlled colonies because the metropoles were Christians. Historian Philip Hoffman calculated that by 1800, before the Industrial Revolution, Europeans already controlled at least 35% of the globe, and by 1914, they had gained control of 84% of the globe.
In the aftermath of World War II, colonial powers were forced to retreat between 1945–1975, when nearly all colonies gained independence, entering into changed colonial, so-called postcolonial and neocolonialist relations. Postcolonialism and neocolonialism has continued or shifted relations and ideologies of colonialism, attempting to justify its continuation with adjusted narratives like development and new frontiers, as in exploring outer space for colonization.
Collins English Dictionary defines colonialism as "the policy and practice of a power in extending control over weaker peoples or areas". Webster's Encyclopedic Dictionary defines colonialism as "the system or policy of a nation seeking to extend or retain its authority over other people or territories". The Merriam-Webster Dictionary offers four definitions, including "something characteristic of a colony" and "control by one power over a dependent area or people". Etymologically, the word "colony" comes from the Latin colōnia—"a place for agriculture".
The Stanford Encyclopedia of Philosophy uses the term "to describe the process of European settlement and political control over the rest of the world, including the Americas, Australia, and parts of Africa and Asia". It discusses the distinction between colonialism, imperialism and conquest and states that "[t]he difficulty of defining colonialism stems from the fact that the term is often used as a synonym for imperialism. Both colonialism and imperialism were forms of conquest that were expected to benefit Europe economically and strategically.", and continues "given the difficulty of consistently distinguishing between the two terms, this entry will use colonialism broadly to refer to the project of European political domination from the sixteenth to the twentieth centuries that ended with the national liberation movements of the 1960s".
In his preface to Jürgen Osterhammel's Colonialism: A Theoretical Overview, Roger Tignor says "For Osterhammel, the essence of colonialism is the existence of colonies, which are by definition governed differently from other territories such as protectorates or informal spheres of influence." In the book, Osterhammel asks, "How can 'colonialism' be defined independently from 'colony?'" He settles on a three-sentence definition:
Colonialism is a relationship between an indigenous (or forcibly imported) majority and a minority of foreign invaders. The fundamental decisions affecting the lives of the colonised people are made and implemented by the colonial rulers in pursuit of interests that are often defined in a distant metropolis. Rejecting cultural compromises with the colonised population, the colonisers are convinced of their own superiority and their ordained mandate to rule.