New historical research has revealed the vast scale of Britain’s involvement in the transatlantic slave trade, documenting the participation of kings and queens, parliamentarians, bankers, merchants, clergy and women investors in a system that trafficked and enslaved Africans for nearly 250 years before the trade was abolished in 1807.
The Guardian, in a series of three detailed reports, said the British Slave Traders Database was the product of a three-year research project led by specialist historians from Lancaster University, the University of Manchester and University College London.
The registry aims to provide the most comprehensive picture yet of the people who financed Britain’s slave trade, drawing on company records, birth, death and marriage certificates, wills, political records and other historical documents.
According to The Guardian, researchers identified around 13,000 people who invested in the British slave trade, from John Hawkins’ earliest voyages in the 1560s until the trade was abolished in 1807.
The research indicates that British ships and trading networks abducted more than three million African men, women and children and forcibly transported them across the Atlantic to colonial plantations in the Americas and the Caribbean.
The trade was neither a marginal nor secret activity. It was tied to the monarchy, Parliament, financial institutions and commercial elites, while its profits and influence spread across broad sections of British society, according to The Guardian.
Kings, Queens and Investors
The registry and related research reveal the depth to which the slave trade was embedded in the institutions of the British state.
The royal family was directly involved. British kings, queens and senior royal figures, beginning with Queen Elizabeth I and continuing under later monarchs, helped lead and finance trading companies including the Royal African Company. Enslaved Africans were at times branded into their bodies with the symbol of the royal crown.
More than 100 members of Parliament invested in slave-trading companies. They included politicians from both the Tory and Whig parties, the historical predecessors of today’s Conservative Party and Liberal Democrats.
Major financial institutions were also connected to the trade. Dozens of early founders and directors of the Bank of England were investors in slave trading.
The Church of England was implicated as well, with researchers documenting 45 clergymen who held shares or invested in the Royal African Company.
The database also identifies around 1,000 women among the investors and shareholders who profited from the trade.
Among the prominent names appearing in the registry are King James II, composer George Frideric Handel and philosopher John Locke. Both Handel and Locke held shares in the Royal African Company.
The royal role stretched back to the 16th century, when Queen Elizabeth I supported voyages by licensed privateer John Hawkins to transport enslaved Africans. According to The Guardian, she supplied him with Royal Navy vessels in return for a share of the profits.
After the restoration of the monarchy in 1660, royal involvement became more systematic as Crown-chartered companies were established specifically for trading in Africans.
The Royal African Company, founded in 1672, became the largest of these enterprises, transporting at least 150,000 African men, women and children across the Atlantic, according to the research.
King James II, then Duke of York, served as the company’s governor and was a major shareholder. His cousin, Prince Rupert, was also a leading participant. Company meetings where decisions concerning the slave trade were made were held in James’ private apartment at Whitehall Palace.
A Profitable Trade and a Deadly System
The system extended far beyond monarchs and London elites, reaching Britain’s coastal cities, particularly Bristol and Liverpool.
Records show that merchant Richard Farr, originally a Bristol rope-maker who became one of the region’s best-known slave traders, equipped at least 38 ships that transported more than 10,000 people to plantations.
James Laroche, over 42 years until his death in 1770, outfitted at least 105 ships for slave-trading voyages. Those vessels carried more than 30,000 people into captivity.
In Liverpool, which became a major centre of the trade in enslaved Africans from around 1750, Professor Edmond Smith of the University of Manchester, one of the project’s senior researchers, found that 51 of the city’s mayors had been involved in the slave trade.
Liverpool authorities also repeatedly lobbied Parliament against abolition.
Among the most prominent figures was Arthur Heywood, who participated in 80 voyages between 1744 and 1780, transporting about 21,648 African captives to colonies and ports in the Americas and Caribbean. He later established a bank bearing his family name, according to the report.
Merchant William Earle participated in 117 voyages that transported an estimated 36,565 enslaved Africans. His family became one of Britain’s most prominent slave-trading dynasties, according to the registry.
The voyages themselves were exceptionally brutal.
Records show that Robert Heshham and his brother William transported around 9,000 enslaved Africans, of whom approximately 1,350 died because of the harsh conditions aboard the ships.
The SlaveVoyages database also shows that the South Sea Company transported 43,220 African captives from West Africa and Madagascar to the Caribbean and Spanish-controlled territories in the Americas between 1714 and 1740.
Around 7,000 people died aboard the company’s ships. The company also transported more than 50,000 enslaved people within the Americas.
Slavery as State Policy
The Guardian reported that enslaved Africans were held in bondage for life and forced to work without pay under extreme violence, producing commodities such as sugar and tobacco that became central to European consumption.
In 1750, Parliament passed legislation that ended the existence of the Royal African Company and entrenched a system of so-called free trade in Africans, after the company’s monopoly had already been dismantled in stages since the late 17th century.
The law stated that trade with Africa was necessary to provide plantations and colonies with sufficient numbers of Africans at what it described as “reasonable” prices, while declaring the trade open to all subjects of the Crown.
According to The Guardian, this effectively made the slave trade an openly declared element of British state economic policy.
The trade was also tied to British manufacturing during the Industrial Revolution. Merchant ships departed Britain carrying goods, including weapons manufactured in Birmingham, which were exchanged in West Africa for enslaved Africans before they were transported to the colonies.
The Money Built on Slavery
When Parliament abolished slavery across most of the British Empire in 1833, the British government paid around £20 million in compensation to slave owners for the loss of people who were legally treated as their “property”.
Using the lowest calculation cited by The Guardian, that sum would be worth around £2.7 billion today, or approximately US$3.6 billion.
The people who had been enslaved received no compensation.
Research indicates that wealth accumulated through slavery became embedded throughout British society, funding hospitals, schools, welfare institutions, the arts, science and culture.
In a striking contradiction, wills examined by the project show that hundreds of slave-trade investors also left money to the poor through churches and local institutions.
Branded With the Crown
Separate research conducted as part of the project has exposed an even harsher dimension of the monarchy’s involvement.
Historian Nicholas Radburn of Lancaster University discovered a 1714 letter from the board of the South Sea Company to its agents in Buenos Aires instructing them to brand enslaved people with a metal instrument bearing the British Crown symbol.
Radburn said the letter showed that members of London’s elite were discussing in detail how violence should be inflicted on enslaved people overseas.
The letter stated:
“You now appear not to mark the slaves, the reason being that the French did not do so, and that Dr Dover said your mark, being so large, might endanger the slaves.”
The board insisted its agents disregard the doctor’s advice, writing that branding with heated metal was “the most effectual way” to distinguish “our slaves” from others.
The directors sent a crown-shaped brand with the letter and included instructions on how it should be used to scar the bodies of enslaved Africans.
They wrote:
“We enclose you a small silver mark. As to the manner of using it, the method practised at our other factories is to mark the slaves on the left shoulder after heating the mark until red hot.”
The letter was signed: “Your affectionate friends, the Court of Directors,” according to The Guardian.
Growing Demands for Justice
The publication of the registry comes amid growing debate over reparations and formal apologies for slavery.
In March 2026, a large majority of countries at the United Nations voted in favour of a Ghana-led declaration describing the historical trafficking and enslavement of Africans as “the gravest crime against humanity”, according to The Guardian.
Britain abstained from the vote, arguing that the wording created a “hierarchy of historical atrocities” and maintaining that slavery and the slave trade were not violations of international law at the time.
The report also noted that an official Jamaican delegation last week submitted a petition to King Charles seeking a legal opinion on the legitimacy of Britain’s position on reparations.
The petition asked whether the forced transportation of Africans to Jamaica constituted a crime against humanity and whether Britain was legally obliged to provide reparations for slavery and its continuing effects.
Charles has previously described slavery as an “appalling atrocity”, but has not issued a formal apology for the role played by Britain or the monarchy.
Responding to The Guardian investigation, a spokesperson for the King said Charles was “grateful” to researchers working on the issue and contributing to debate over how these questions should be addressed.
The British Slave Traders Database therefore documents a system in which royal, political and economic institutions profited from the enslavement of millions of Africans, while Britain has still not issued a formal apology for its role and successive governments have resisted opening negotiations over reparations.
As historical documents continue to expose the depth of elite and royal involvement, the unresolved question is whether slavery’s legacy truly ended with abolition, or whether the wealth, institutions and relationships built through it remain embedded in modern Britain.
