This timeline outlines some of the events around the world that have caused migration to Britain since the 1770s. It also presents key pieces of legislation relating to migration during this time.
This timeline does not cover all migrational history
As a result of the transatlantic slave trade the number of African men, women and children resident in Britain in 1770 was approximately 14,000, but few of them had real freedom.
In 1807, Parliament banned the slave trade - but not slavery itself. In 1833, Parliament banned all slavery across the British Empire. Abolition meant a virtual halt to the arrival of black people to Britain.
Between 1830 and 1850, tens of thousands of Irish arrived in Britain. Mass migration resulted from the Irish Potato Famine in the mid-1840s.
More than 150,000 Jews from east Europe settled in Britain. Repeated waves of pogroms (riots or massacres) against Jews in the Russian Empire from 1881 caused many to flee.
'Undesirable immigrants', particularly those with no means of supporting themselves, could be refused entry to Britain. Exceptions were made for people fleeing persecution on religious or political grounds.
250,000 Belgian refugees arrived in Britain escaping the fighting of the First World War. By 1921 less than 10,000 remained in Britain, most having returned home.
The Russian Revolution in 1917 was followed by civil war and the creation of the Soviet Union in 1922. 15,000 Russian émigrés came to Britain between 1918-31.
During the Spanish Civil War, Britain accepted 3,889 Basque children evacuated from the war zone. The Government agreed providing there was no cost to the state and their stay was temporary.
Between 1933-39, 55,000 European Jews fleeing Nazi regimes arrived in Britain, the majority in 1938-39. To enter they needed to have a job or a sponsor in Britain. Between December 1938 and September 1939, 9,354 children were rescued through an organised scheme called the 'Kindertransports'.
135,000 displaced Poles, many of whom had fought alongside Britain during the Second World War, settled in Britain rather than return to Poland under a new Soviet-controlled government.
United Nations Universal Declaration of Human Rights: The Declaration declared; 'Everyone has the right to seek and to enjoy in other countries asylum from persecution.' (Article 14.1, UN Universal Declaration of Human Rights, 1948)
Migrants arrived in Essex on the SS Empire Windrush marking the start of a major period of migration. Many men from the West Indies (then part of the British Empire) had fought for the "mother country" during World War Two. Their sense of patriotism, coupled with the need to find work, steered them towards the UK. Legislation allowed people from the Empire and Commonwealth unhindered rights to enter Britain because they carried a British passport.
United Nations Convention Relating to the Status of Refugees: The Convention set out standards for the treatment of refugees. Governments who signed it agreed not to return refugees to places where they would be in danger. A refugee is a person with 'a well-founded fear of being persecuted for reasons of race, religion, nationality, membership of a particular social group or political opinion'. (UN Convention Relating to the Status of Refugees, 1951)
The growing persecution of Asian people in Kenya led an increasing number to flee to Britain. Quotas for the number of East African Asians who could enter Britain were introduced with the passing of the 1968 Commonwealth Immigrants Act.
In 1971 General Idi Amin came to power in a military coup (takeover of government). Brutal ethnic persecution, especially of the Acholi and Langi people, forced many to flee. In 1972 Idi Amin expelled all Asians from Uganda. Many held British passports and 28,608 came to Britain.
In 1974-5 a Kurdish uprising against the Iraqi government was repressed, with the government destroying villages and forcibly moving Kurds to barren land in the south. This resulted in people fleeing into neighbouring countries and eventually Europe and Britain. [The Kurdish people do not have an officially recognised country. They live in a geographical and cultural region referred to as Kurdistan, which includes parts of four countries - east and south eastern Turkey, northern Iraq, western Iran and northern Syria.]
In the late 1960s and 1970s opposition against the Shah (the head of the Royal Family in Iran) was crushed by his secret police and opponents were forced into exile. In 1979 Ayatollah Khomeini came to power in the Islamic Revolution and installed Islamic law. There was widespread political oppression, persecution of Kurdish and Baha'i minorities, and strict restrictions placed upon women. Since the late 1970s the number of people from Iran seeking asylum in Britain has remained high.
In 1961 the Eritrean Liberation Front was founded to fight for independence from Ethiopia. The war between Ethiopia and the Eritrean liberation movement intensified in the 1970s and continued through the 1980s, forcing many people to flee.
1971 Immigration Act: The power to hold asylum seekers in detention centres or prisons was introduced for the first time.
In Iraq, after the 1991 Gulf War, people in the Shi'ite dominated south and Kurds in the north rebelled against Saddam Hussein. The rebellions were brutally suppressed, with mass executions, bombardments and thousands of civilian deaths. Huge numbers of people fled.
In 1998-2000 Ethiopia and Eritrea fought a border war. Ethiopia expelled Eritreans and people of Eritrean origin. Many people in mixed marriages or of mixed descent found themselves unwelcome and persecuted in both countries.
The collapse of communist Yugoslavia in 1992 created civil breakdown, ethnic conflict, military occupation and 'ethnic cleansing'. As well as refugees coming to Britain as individuals, between 1992-6 over 3,000 Bosnians came as part of a programme organised by the British government.
Joseph Mobutu, President of the Democratic Republic of Congo, who had been in power since a military coup (takeover) in 1965, continued his harsh repression of political opponents into the 1990s. The number of people from the country seeking asylum in Britain sharply increased from 1989. In 1997 the government was overthrown and the following year civil war broke out.
The Taliban, in Afghanistan, rose to power in 1996, out of the civil war. Many people fled the oppressive and violent regime of the Taliban, with the number of Afghans seeking asylum in Britain greatly increasing after 1997.
Dublin Convention: European Union countries could deport asylum seekers who had travelled via another 'safe' EU country back to that country.
Asylum and Immigration (Appeals) Act: Unsuccessful asylum seekers had the right to go to appeal, although there were strict time limits. All asylum seekers had to be fingerprinted, they could be detained, and rights to council housing were restricted.
Immigration and Asylum Act: The National Asylum Support Service (NASS) was set up as an alternative benefits and housing system for asylum seekers. Originally it supported asylum seekers through vouchers which could be exchanged in some shops. This was later replaced by cash worth 70% of income support. NASS was also given responsibility for dispersing asylum seekers around the country.
Eritrea is now a one-party state, tolerating no political opposition. Eritreans continue to flee political oppression and human rights abuses by the government.
Opposition to the ruling Zanu PF party is met with harsh reprisals and there is no freedom of the press. Since 2000 the number of Zimbabweans seeking asylum in the UK has been rising and in the first quarter of 2006 Zimbabweans were the largest group to seek asylum.
European law: Since 2004, Britain's workforce has been fed by new recruits from Eastern Europe, with almost 600,000 migrants from the newly accessioned states successfully taking up employment here.
More than a million Poles are estimated to have left their country, tempted to Britain by the promise of higher wages and an economy desperately short of numbers and skills.
According to Home Office statistics, in the first half of 2006, 11,945 people applied for asylum in Britain. The top ten countries from which asylum applicants came were: Eritrea, Zimbabwe, Afghanistan, Iran, China, Somalia, Nigeria, Pakistan, India, Sudan.
The Right to Work: The right of asylum seekers to work was removed. Previously they had been able to apply for permission to work after they had been in Britain for six months.
The Nationality, Immigration and Asylum Act focussed on the control and removal of people whose claims were unsuccessful. English language and citizenship tests were introduced for people applying for British nationality.
Leave to Remain: Since August 2005, refugees are no longer given indefinite (ie permanent) leave to remain when their claims are accepted. Instead they are only given permission to stay for five years. After five years they can apply for indefinite leave to remain.