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What is colonialism? An explainer

Colonialism: its origins, expansion, legacy and key academic critiques. Dr Colin Alexander, of the School of Social Sciences, provides a brief history of colonialism

By Dr Colin Alexander | Published on 19 October 2026

Categories: Press office; Research; School of Social Sciences;

An image depicting colonialism
An image depicting colonialism

What you need to know:

  • The word ‘colonialism’ comes from the Latin ‘colonia’, which was what the Roman Empire called settled land outside of Italy.
  • When historians refer to the ‘colonial era’ they are usually referencing the period of European territorial expansion from 1453 – when the Islamic Ottoman Empire captured Constantinople (modern day Istanbul) – and the end of World War II in 1945 when most European nations began to relinquish direct sovereign control over their colonial territories.
  • Perhaps the most famous explorer of the colonial era is Christopher Colombus – born in Genoa, Italy, but working for a syndicate based in Seville, Spain – whose ship the Santa Maria landed in the Americas in 1492.
  • Slavery, the slave trade and forced or indentured labour have been the most potent criticisms of the colonial era.

What is colonialism?

Colonialism refers to the practice of seizing and then controlling land and its natural resources beyond a nation-state’s defined territory. The territory then becomes a ‘colony’ of that nation-state and the people become ‘subjects’ rather than ‘citizens’. To this end, colonialism may be defined as rule by outsiders for the benefit of outsiders.

Colonial empires have operated under different political structures, guises and justifications. However, the economic imperative that underpins all colonial enterprise is consistent throughout. This is despite varied propaganda to disguise its financial fundamental and the hardships, restrictions and sometimes violence imposed upon native peoples. For example, colonial expansion into Africa talked about ‘civilising’ people and ‘spreading the word of God’ and played down the focus upon extraction of natural resources and other economic concerns.

What is the history of colonialism?

The Portuguese were the first European nation to advance their colonial interests using naval capabilities to sail around the Cape of Good Hope and Cape Horn. Captains and Admirals like Prince Henry the Navigator, Bartholomew Diaz, Vasco de Gama and Ferdinand Magellan remain famous today for their early explorations during the late 1400s and early 1500s.

Despite starting slightly later than other European nations like Spain and Portugal, the United Kingdom developed the largest colonial empire in history – by 1920 it controlled almost a quarter of all land on the planet. This was despite the American Revolutionary War of the 1770s and 80s, which uncoupled the colonies of North America from British rule and ultimately led to the creation of what is now known as the United States of America.

The English, and then British (following the Act of Union between Scotland and England in 1707), era of significant colonial expansion began during the early 1600s with the founding of the English East India Companies.

A crucial moment in British colonial history occurred in 1662 when Catherine of Braganza (daughter of Portuguese King John IV) married Charles II of England. Catherine’s marital dowry included the Portuguese territories of Tangier in modern-day Morocco and Bombay in modern-day India. The provision of Bombay served as a catalyst towards British expansion into South Asia and what eventually became complete domination of that region.

A key moment in the history of colonialism was the British East India Company’s victory over the Nawab of Bengal at the Battle of Plassey in 1757. This marked the start of British dominance in India and allowed for the unrivalled extraction of natural resources from the subcontinent that were essential for the industrial revolution that began in the 1760s.

Despite being largely outlawed by the mid-1800s, the impact of the Atlantic slave trade and issues related to it – racism, inequalities, injustices and other prejudices – are still experienced today around the world. The slave trade was entwined with industry, with many slaves transported to the Americas to work on sugar, cotton and tobacco plantations.

A common perception exists that the colonial era is over and that formerly colonised territories have now been granted sovereignty. There remain exceptions to this though. For example, the cause of Irish republicanism argues that Northern Ireland remains a colonial territory of Great Britain.

What are the key arguments on colonialism?

One of the most well-known early critiques of colonialism is from J. A. Hobson. Originally published in 1902, he discusses the resentment that those made to be colonial subjects feel towards the outsiders who rule them.

'Not only does aggressive Imperialism defeat the movement towards internationalism by fostering animosities among competing empires: its attack upon the liberties and the existence of weaker or lower races stimulates in them a corresponding excess of national self-consciousness. A nationalism that bristles with resentment and is all astrain with the passion of self-defence is only less perverted from its natural genius than the nationalism which glows with animus of greed and self-aggrandisement at the expense of others. From this aspect aggressive imperialism is an artificial stimulation of nationalism in peoples too foreign to be absorbed and too compact to be permanently crushed.' (Hobson, 2005: 11)

Hobson’s critique of imperialism, and the colonial practices of the British in particular, was a landmark study and went some way to contesting the narrative of Social Darwinism that had gained a significant following during the late nineteenth and early twentieth centuries. However, Hobson’s study was less a critique of the practice of colonialism itself but an examination of the reasoning behind a state’s decision to colonise in the first place.

Edward Said, in his landmark text ‘Orientalism’, discussed the racial divisions that came to define colonialism. Said argued that, rather than an extension of class-based domestic politics, colonialism was a different form of governance and society where the physical differences between ruler and the ruled were often unmistakeable.

'Being a white man was therefore an idea and a reality. It involved a reasoned position towards both the white and the non-white worlds. It meant – in the colonies – speaking in a certain way, behaving according to a code of regulations, and even feeling certain things and not others. It meant specific judgments, evaluations, [and] gestures. It was a form of authority before which non-whites, and even whites themselves, were expected to bend. In the institutional forms it took (colonial governments, consular corps, commercial establishments), it was an agency for the expression, diffusion and implementation of policy towards the world, and within this agency, although a certain personal latitude was allowed, the impersonal communal idea of being a white man ruled.' (Said, 1978: 230)

Another key writer on colonialism is Albert Memmi. Originally written in 1957 during the Algerian War of Independence from France, his most famous book, ‘The Colonizer and the Colonized’, argues that participation in a colonial administration can lead to the destruction of the humanity of the colonizer.

'In short, [the colonizer] knows, in his own eyes as well as those of his victim, that he is a usurper. He must adjust to both being regarded as such, and to this situation.' (Memmi, 2004: 53)

Henceforth, Memmi discusses how the colonizer ‘discovers’, assuming that they were not aware of such circumstances before they arrived in the colony, that their life is to be one of ‘profit’, ‘privilege’ and ‘usurpation’. Indeed, it may be that their expectations of the colonial experience are different from the lived reality they come to experience. This is because colonialism was often tacitly and explicitly supported through various forms of propaganda and popular media within the colonising state. Thus, whether consciously or sub-consciously, the colonizer faces a challenge if they are to thrive in the colonial environment. They can continue to participate in the colonial system on motivations framed beyond economics, for example, the spread of Christianity. They can become circumstantially blind to the plight of the colonized or to rationalise it as their own doing. They can sub-humanise those who they rule as lesser beings. Or they can absolve themselves of responsibility by saying that they are just executing the orders of others. Ultimately, as Memmi’s work explains, the humanity and soul of the colonizer is usually harmed by participation in the colonial enterprise.

Dr Colin Alexander is Senior Lecturer in Political Communications within the School of Social Sciences. He is the Course Leader for the Masters in Global Media and Communications, which is taught primarily at NTU's City Campus. His research interests include propaganda, public diplomacy, the role of charity and philanthropy in society, critical journalism studies, China and Taiwan, North Korea, colonialism and colonial India, He has supervised, and is currently supervising, PhD projects on several topics close to his research interests and welcomes inquiries.