Slavery in Britain existed even before the Roman period from AD 43 to AD 410, and the practice endured in various forms in the English overseas possessions and much of the British Empire until the 19th century. English merchants, especially from the ports of Liverpool, London, and Bristol, controlled a significant part of the Transatlantic slave trade, until the Slave Trade Act 1807 prohibited the Atlantic slave trade in the British Empire. After the act was passed, Britain interdicted the international transatlantic slave trade both diplomatically and with the Royal Navy's West Africa Squadron, established in 1808. After the ending of the Napoleonic Wars in 1815, the Royal Navy had the ships available to back up diplomatic efforts to end slavery, by both increasing resources for the West Africa Squadron from 1818 and, when diplomatic pressure on the Barbary corsairs proved insufficient, by bombarding Algiers in 1816 in a ferocious engagement.
In England the Norman Conquest resulted in the gradual merger of the pre-conquest institution of slavery into serfdom in the midst of other economic upheavals. Given the widespread socio-political changes afterwards, slaves were no longer treated differently from other individuals in either English law or formal custom. By the middle of the 12th century, the institution of slavery as it had existed prior to the Norman conquest had fully disappeared, but other forms of unfree servitude continued for some centuries.
English merchants were a significant force behind the Atlantic slave trade between the seventeenth and nineteenth centuries, but no legislation was passed to either formally legalize or abolish chattel slavery in the British Isles. Instead, the common law system, based on laws established since the Norman conquest governing legal protections of individuals, protected those residing in England from any formal form of slavery, and a formal legal precedent against the practice, extending to those who may have been enslaved under foreign jurisdictions, was eventually established by Somerset v Stewart (1772) 98 ER 499. In Scotland, Coal mining slaves were still in use until 1799, when the Colliers (Scotland) Act 1799 established their freedom and made slavery and bondage unlawful.
An abolitionist movement grew in Britain during the 18th and 19th centuries, and the Slave Trade Act 1807 prohibited the involvement of British subjects in the Atlantic slave trade. The Slavery Abolition Act 1833 abolished slavery in most of the British Empire, including Great Britain and Ireland. Drescher, Seymour. Abolition: A History of Slavery and Antislavery (2009) Hinks, Peter, and John McKivigan, eds. Encyclopedia of Antislavery and Abolition (2 vol. 2006) Huzzey, Richard. Freedom Burning: Anti-Slavery and Empire in Victorian Britain. (Cornell University Press, 2012) 303pp.
Despite being contrary to the laws of the United Kingdom, practices described as "modern slavery" still exist in Britain and have often involved the effects created by human traffickers attacking those from poorer countries, such as those undertaking various crimes victimising Vietnamese nationals. At the same time, multiple groups within the organised crime networks in the UK have frequently targeted British nationals. The country's government has, in a public statement, noted how "gangs exploit vulnerable individuals to transport [illegal] substances", and "who is recognised as a victim of modern slavery" includes both men and women as well as children. Specifically, in 2022, a full "12,727 potential victims of modern slavery were referred to the Home Office in 2021, representing a 20% increase compared to the preceding year".
Overview
Historically, Britons were enslaved in large numbers, typically by rich merchants and warlords who exported indigenous slaves from pre-Roman times,Strabo, Geographica, book 4, chapter 5: "Britain, Ireland, and Thule". http://penelope.uchicago.edu/Thayer/E/Roman/Texts/Strabo/4E*.html – "It bears grain, cattle, gold, silver, and iron. These things, accordingly, are exported from the island, as also hides, and slaves, and dogs" and by foreign invaders from the Roman Empire during the Roman Conquest of Britain..David A. E. Pelteret, Slavery in Early Mediaeval England: From the Reign of Alfred until the Twelfth Century (1995)
The Norman Conquest of England in 1066 accelerated the decline of outright slavery, a practice present in Anglo-Saxon England, by replacing it with a more structured manorial system of serfdom. While not abolishing the existing status of theows (slaves), the Normans' administrative focus, exemplified by the Domesday Book (1086), which meticulously recorded them as property, inadvertently contributed to their gradual absorption into the unfree peasant class. Modern scholarship suggests this shift was driven less by moral imperative and more by economic and administrative efficiency, as serfdom (villeinage) provided a more stable and controllable labour force for the new Norman aristocracy.
In the 17th century English merchants began to take part in the Atlantic slave trade. As part of the triangular trade-system, ship-owners transported enslaved West Africans to European possessions in the New World (especially to British colonies in the West Indies) to be sold there. The ships brought commodities back to Britain then exported goods to Africa. Some plantation owners brought slaves to Britain, where many of them ran away from their masters. After a long campaign for abolition led by Thomas Clarkson and (in the House of Commons) by William Wilberforce, Parliament prohibited dealing in slaves by passing the Slave Trade Act 1807, which the Royal Navy's West Africa Squadron enforced. Britain used its influence to persuade other countries around the world to abolish the slave trade and to sign treaties to allow the Royal Navy to interdict slaving ships.
In 1772, Somerset v Stewart held that slavery had no basis in English law and was thus a violation of habeas corpus. This built on the earlier Cartwright case from the reign of Elizabeth I, which had similarly held the concept of slavery was not recognised in English law. This case was generally taken at the time to have decided that the condition of slavery did not exist under English law. Legally ("de jure") slave owners could not win in court, and abolitionists provided legal help for enslaved black people. However actual ("de facto") slavery continued in Britain with ten to fourteen thousand slaves in England and Wales, who were mostly domestic servants. When slaves were brought in from the colonies they had to sign waivers that made them indentured servants while in Britain. Most modern historians generally agree that slavery continued in Britain into the late 18th century, finally disappearing around 1800.
Slavery elsewhere in the British Empire was not affected — indeed it grew rapidly especially in the Caribbean colonies. Slavery was abolished in the directly governed colonies, like Canada or Mauritius, through buying out the owners from 1834, under the terms of the Slavery Abolition Act 1833. Most slaves were freed, with exceptions and delays provided for territories administered by East India Company, in India, Ceylon, and Saint Helena. These East India Company exceptions were eliminated in 1843, though slave holdings, within the indirectly ruled Indian Princely states, were still being captured by the 1891 Census of India. While in indirectly ruled British Protectorates, incorporated after this date, like the Colony and Protectorate of Nigeria (1914–1954), Sudan (1899–1956), Maldives, Trucial States (UAE), Qatar, Bahrain and Kuwait, slavery remained legally permissible, under local Sharia legal codes, for the majority of the twentieth century.
The prohibition on slavery and servitude is now codified under Article 4 of the European Convention on Human Rights, which came in force in 1953 and built on past precedents already established in the United Kingdom. These clauses and practices were further incorporated directly into United Kingdom law by the Human Rights Act 1998. Article 4 of the Convention also bans forced or compulsory labour, with some exceptions such as a criminal penalty or military service. The UK Modern Slavery Act of 2015 was also enacted to help counter the rise of modern ("de facto") slavery practices, with an estimated 122,000 living in modern slavery in 2023 (approximately 0.18% of total UK population), and consist of individuals predominantly of migrant heritage. When compared to the 10 to 14 thousand figure of "de facto" slavery in the late 18th century for England and Wales, constituting 0.15-0.18% of the total population of around 8 million, this demonstrates a resurgence in "de facto" slavery practices in the early 21st century to pre-1800 levels.
History
Before 1066 From before Roman times, slavery was prevalent in Britain, with indigenous Britons being routinely exported.Strabo, Geographica book 4 chapter 5: Britain, Ireland, and Thule. http://penelope.uchicago.edu/Thayer/E/Roman/Texts/Strabo/4E*.html "It bears grain, cattle, gold, silver, and iron. These things, accordingly, are exported from the island, as also hides, and slaves, and dogs" Following the Roman conquest of Britain, slavery was expanded and industrialised.
After the fall of Roman Britain, both the Angles and Saxons propagated the slave system.Freeman, E.A. (1869) Old English History for Children, MacMillan, London, pp. 7, 27–28 One of the earliest accounts of slaves from early medieval Britain come from the description of fair-haired boys from York seen in Rome by Pope Gregory the Great, in a biography written by an anonymous monk. Pagan Angles and Saxons were known to be exported from the British Isles over the English channel to Arras and Tournai and then across France to the Mediterranian via the great slave port of Marseilles.Phillips, W. D. (1985). Slavery from Roman Times to the Early Transatlantic Trade. Storbritannien: Manchester University Press. p. 60-61 It is known that the Frisian slave dealers visited Anglo-Saxon London during the 7th and 8th centuries to purchase slaves, which they then sold along the river ways to the German cities and Southward to Paris.
Vikings traded with Gaelic, Pict, Brythonic and Saxon kingdoms in between raiding them for slaves. Saxon slave traders sometimes worked in league with Norse traders, often selling Britons to the Irish. In 870, Vikings besieged and captured the stronghold of Alt Clut (the capital of the Kingdom of Strathclyde) and in 871 most of the site's inhabitants were taken, most probably by Olaf the White and Ivar the Boneless, to the Dublin slave markets.The Historical encyclopedia of world slavery, Volume 1; Volume 7 By Junius P. Rodriguez ABC-CLIO, 1997 Maredudd ab Owain (d. 999) is said to have paid a large ransom for the return of 2,000 Welsh slaves.
England and the British Isles were also used as a slave supply source by the Vikings, who were one of the main suppliers of saqaliba slaves to Islamic Spain. People taken captive during the Viking raids in the British Isles, such as the Ireland, could be sold to Moorish Spain via the Dublin slave trade.
Anglo-Saxon opinion eventually turned against the sale of slaves abroad: a law of Ine of Wessex stated that anyone selling his own countryman, whether bond or free, across the sea, was to pay his own weregild in penalty, even when the man sold was guilty of a crime.H. R. Loyn, Anglo-Saxon England and the Norman Conquest, 2nd ed. 1991:90. Nevertheless, legal penalties and economic pressures that led to default in payments maintained the supply of slaves, and in the 11th century there was still a slave trade operating out of Bristol, as a passage in the Vita Wulfstani makes clear.Noted by Loyn 1991:90 note 39.