British diaspora

The British diaspora consists of people of English, Scottish, Welsh, Northern Irish, Cornish, Manx and Channel Islands ancestral descent who live outside of the United Kingdom and its Crown Dependencies.

In 2008, the United Kingdom's Foreign and Commonwealth Office estimated that at least 80% of New Zealanders had some British ancestry, however at the 2018 census only 70% of New Zealanders identified as having some European ancestry. Up to 76% of Australians, 48% of Canadians, 33% of Americans, and 3% of South Africans have ancestry from the British Isles. Additionally, at least 270,000 Argentines have some British ancestry. More than 300,000 Indians have some British ancestry, but comprise less than 0.1% of India's population.

The British diaspora includes about 200 million people worldwide. Other countries with over 100,000 British expatriates include the Republic of Ireland, Spain, France, Germany, and the United Arab Emirates.

Up to the 19th century
The first documented exodus of Britons began during the Anglo-Saxon invasion of Great Britain. A large number of Brythonic-speaking Celts fled or migrated to what is now Brittany on the coast of France, becoming the Bretons.

The second large-scale British migration came following the Norman Conquest of England, leading to a displacement of English people, mostly dispossessed nobility. They settled in neighboring regions including Ireland and Scandinavia, and as far east as Crimea and Anatolia in the Byzantine Empire. Englishmen eventually replaced Scandinavians as the main source of recruitment for the Byzantine Emperor's personal Varangian Guard.

After the Age of Discovery, the various peoples of the British Isles, and especially the English, were among the earliest and by far the largest communities to emigrate out of Europe. Indeed, the British Empire's expansion during the first half of the 19th century saw an extraordinary dispersion of the British people, with particular concentrations in Australasia and North America.

The British Empire was "built on waves of migration overseas by British people", who left Great Britain, later the United Kingdom, and reached across the globe and permanently affected population structures in three continents. As a result of the British colonisation of the Americas, what became the United States was "easily the greatest single destination of emigrant British", but in what would become the Commonwealth of Australia the British experienced a birth rate higher than anything seen before, which together with continuing British immigration resulted in a huge outnumbering of indigenous Australians.

In colonies such as Southern Rhodesia, British Hong Kong, Singapore, Jamaica, Barbados, Malaysia, and the Cape Colony, permanently resident British communities were established, and while never more than a numerical minority, these Britons exercised a dominant influence upon the culture and politics of those lands. In Australia, Canada, and New Zealand, people of British origin came to constitute the majority of the population, contributing to these states becoming integral to the Anglosphere.

The British not only emigrated to parts of the British Empire, but also settled in large numbers in parts of the Americas, particularly in the United States and in sizeable numbers in Argentina, Chile and Mexico.

The United Kingdom census, 1861 estimated the number of overseas British to be around 2.5 million. However, it concluded that most of these were "not conventional settlers" but rather "travellers, merchants, professionals, and military personnel". By 1890, there were over 1.5 million further British-born people living in Australia, Canada, New Zealand, and South Africa.

British diaspora today
According to The Foreign and Commonwealth Office, there were 13.1 million British nationals living abroad in 2004–05. These figures are taken from the consular annual returns from overseas posts. There is no requirement for UK citizens to register with British missions overseas, so these figures are therefore based on the most reliable information that can be obtained, e.g. from host government official statistics.

A 2006 publication from the Institute for Public Policy Research estimated that 5.5 million British-born people lived outside the United Kingdom.

In terms of outbound expatriation, in 2009, the United Kingdom had the most expatriates among developed OECD countries, with more than three million British living abroad, a figure followed by Germany and Italy. On an annual basis, emigration from Britain has stood at about 400,000 per year for the past 10 years.

Living abroad as an expatriate can affect certain rights. In particular:
 * can only vote in general elections if they have been on a British electoral register at some point in the past 15 years. Otherwise, they are not eligible to vote. This Briefing Paper provides information on the eligibility to vote in UK Parliamentary elections for British citizens living overseas and the government's plans to end the 15-year rule – it's 'votes for life' policy.
 * The British Mental Health Act 1983 rules that persons resident abroad do not qualify as "nearest relative" of a person who is ordinarily resident in the United Kingdom, the Channel Islands or the Isle of Man.

Distribution
[[File:Map of the British Diaspora in the World.svg|thumb|300x300px|Map of the British diaspora in the world by population (includes people with British ancestry or citizenship).

{{Legend|#000000|United Kingdom}} {{Legend|#000b44|+ 10,000,000}} {{Legend|#002a9e|+ 1,000,000}} {{Legend|#366bff|+ 100,000}} {{Legend|#7bb1ff|+ 10,000}}]] The earliest migrations of Britons date from the 5th and 6th centuries AD, when Brittonic Celts fleeing the Anglo-Saxon invasions migrated what is today northern France and north western Spain and forged the colonies of Brittany and Britonia. Brittany remained independent of France until the early 16th century and still retains a distinct Brittonic culture and language, whilst Britonia in modern Galicia was absorbed into Spanish states by the end of the 9th century AD.

Britons – people with British citizenship or of British descent – have a significant presence in a number of countries other than the United Kingdom, and in particular in those with historic connections to the British Empire. After the Age of Discovery, the British were one of the earliest and largest communities to emigrate out of Europe, and the British Empire's expansion during the first half of the 19th century triggered an "extraordinary dispersion of the British people", resulting in particular concentrations "in Australasia and North America".

The British Empire was "built on waves of migration overseas by British people", who left the United Kingdom and "reached across the globe and permanently affected population structures in three continents". As a result of the British colonisation of the Americas, what became the United States was "easily the greatest single destination of emigrant British", but in Australia the British experienced a birth rate higher than "anything seen before", resulting in the displacement of indigenous Australians.

In colonies such as Southern Rhodesia, British East Africa and Cape Colony, permanently resident British communities were established and, whilst never more than a numerical minority, these Britons "exercised a dominant influence" upon the culture and politics of those lands. In Australia, Canada and New Zealand, "people of British origin came to constitute the majority of the population", contributing to these states becoming integral to the Anglosphere.

The United Kingdom Census 1861 estimated the size of the overseas British to be around 2.5 million, but concluded that most of these were "not conventional settlers" but rather "travellers, merchants, professionals, and military personnel". By 1890, there were over 1.5 million further UK-born people living in Australia, Canada, New Zealand and South Africa. A 2006 publication from the Institute for Public Policy Research estimated 5.6 million Britons lived outside of the United Kingdom.

Outside of the United Kingdom and its Overseas Territories, up to 76% of Australians, 70% of New Zealanders, 48% of Canadians, 33% of Americans and 3% of South Africans have ancestry from the British Isles. Hong Kong has the highest proportion of British nationals outside of the United Kingdom and its Overseas Territories, with 47% of Hong Kong residents holding a British National (Overseas) status or a British citizenship. The next highest concentrations of British citizens outside of the United Kingdom and its Overseas Territories are located in Barbados (10%), the Republic of Ireland (7%), Australia (6%) and New Zealand (5%).

Note: A different estimate puts China (incl. Hong Kong) ahead with a population of 3,750,000 British citizens, most of which are those in Hong Kong who have continued to possess British nationality, particularly the British nationals (overseas) status, which numbered 3.4 million, through their connection with the former crown colony (see British nationality and Hong Kong for further details).