Guildhall Library Manuscripts Section

London and the Slave Trade

This is Guildhall Library’s first exhibition for Black History Month, and we have begun by looking at the trans-Atlantic slave trade, particularly the profits made by Londoners, and the beginnings of the abolition movement in London. The captions referred to in the text of the leaflet are available at the end of the text.


Britain had limited involvement with the slave trade in the 16th and early 17th centuries, though France and Portugal were more active. However from the late 17th century onwards, a growing number of merchants in London and elsewhere became involved in the slave trade. The Royal African Company was founded in 1672 and was granted a monopoly in trading in slaves, though this was taken away in 1698. Between 1680 and 1686, an average of 5000 slaves a year were transported across the Atlantic.

The shareholders in the Royal African Company included 15 Lord Mayors, 25 sheriffs and 38 aldermen of the City of London (see Profit display case, exhibit 1). London assumed a permanent and central role as the financial hub of the triangular trade by inventing new forms of credit, such as bills payable after three years, to cover the length and financial risks of a typical slave voyage.

Reproduced courtesy of Maps in Minutes and the National Archives, copyright Maps in Minutes and the National Archives.

The horrors of the long journey to the Americas were vividly described by John Newton (see Abolition display case, exhibit 1). Most slave traders tried to squeeze as many slaves as possible into the hold of the ship, in order to increase their profit. Between 1680 and 1688, 23 out of every 100 Africans taken aboard Royal African Company ships died in transit; evidence before the Privy Council in 1789 showed that the average mortality of slaves on the Atlantic crossing was about 12 per cent, plus a further 4.5 per cent between arrival at the port of destination, and sale.

How profitable was the slave trade? This question is still debated by historians, although there were certainly many fortunes made. Early European slave traders captured slaves; later most traded in guns, cloth and iron to buy slaves. Enslaved Africans resisted their enslavement, and the mortality rates in the “Middle Passage” were heavy. There were profits, certainly, but individual merchants could be bankrupted. Highly profitable, however, for European and American slave owners was the use of slave labour on plantations.

Sir William Beckford, 1709-1770, twice Lord Mayor, was the son of a wealthy Jamaican sugar planter and owned more than 22,000 acres in Jamaica. Beckford gave very luxurious banquets as Mayor, described as more elaborate than any since Henry VIII. One banquet alone was said to have cost Beckford £10,000.

Beckford’s popularity in the City was also due to his defence of the City of London’s liberties. He delivered a remonstrance drawn up by the Court of Common Council to King George III, asking him to dissolve Parliament and dismiss his ministers. Beckford also made a speech directly to the King asserting the loyalty of the citizens of London to the Crown and the Constitution. The text of this speech was put on Beckford’s statue in Guildhall (see Profit display case, exhibit 3). Most contemporaries did not see the discordance between Beckford’s immense wealth from slavery and his reputation as a defender of civic liberty, but his slave-owning was occasionally used against him (see Profit display case, exhibit 4).

William Beckford the younger, 1760-1844, was left £1 million in money and £100,000 a year on his father’s death. The younger Beckford is famous for his connoisseurship, his building of a Gothic folly (Fonthill Abbey) and his Gothic novel, Vathek. None of these would have been possible without his father’s money and the continuing revenues from his Jamaican estates, still run with slave labour (see Profit display case, exhibit 5).

Many other London merchants made money from the slave trade and from slave labour. Exhibit 2 in the Profit display case is the letter book for 1767 of Edward Grace and Co, who mainly traded in slaves and oil. Guildhall Library holds other records of this firm. Exhibit 6 is a balance sheet for sugar imported to London in 1837 from the Rosehall Estate, Jamaica, by Davison, Newman & Co. Jamaica was Britain’s most wealthy plantation colony.



In the later 17th and early 18th centuries, slavery and the slave trade were seen by most Londoners – and Britons – as a fact of life. There was no widespread condemnation, and probably little knowledge of the cruel practices or scale of the slave trade.

Lord Mansfield ruled in 1772 that a slave who deserted his master in Britain could not be taken by force to be sold abroad. This verdict led to the decline of slavery in Britain, and the creation of clandestine Black quarters, primarily in poor areas of London such as St Giles in the Fields. By 1800 there were between 15,000 and 20,000 black people living in London, mainly as free men and women, not as slaves or servants.

Early campaigners for the abolition of the slave trade were Evangelical Christians whose primary interest was in saving African souls. One important figure was John Newton, who had been the master of slave ships. He converted to evangelical Christianity in 1748, but continued as a slaver until 1754 when he gave up the sea. He was ordained as a minister in 1764 and became curate at Olney, Buckinghamshire. Gradually he realised the abhorrent nature of the slave trade, and in 1788 wrote his Thoughts on the African Slave Trade to persuade public opinion of its horrors. Because he had been a slaver, his words carried great weight (see Abolition display case, exhibits 1 and 2).

At Olney he became friends with the poet William Cowper, and together they wrote the “Olney Hymns”. Cowper was also an abolitionist, and wrote some effective anti-slavery poems, targeting the economic defence used by the pro-slavery lobby (see Abolition display case, exhibit 3).  

Powerful arguments against slavery were made by some black people who had experienced slavery. In 1787 Ottobah Cugoano published an account of his experiences, Narrative of the Enslavement of a Native of America, and in 1789 Olaudah Equiano wrote The African: The Interesting Narrative of Olaudah Equiano. Equiano worked with Thomas Clarkson and the Society for the Abolition of the Slave Trade, and spoke at many public meetings where he described first-hand the cruelties of the slave trade. As with Newton, Equiano’s personal experience convinced his audience of the truth and importance of his message (see Abolition display case, exhibit 4).

Other prominent abolitionists were Thomas Clarkson and William Wilberforce. Clarkson, a member of the Society for the Abolition of the Slave Trade, organised committees, found evidence for the abolitionist cause, and gave advice and encouragement to hundreds of grass-roots activists. Wilberforce was persuaded by Clarkson and by Newton (who had known him as a child) to take up slavery as a cause. As a result of the Society’s work, over 100 petitions attacking the slave trade were presented to the House of Commons in three months of 1788. William Pitt introduced a parliamentary debate in that year about slavery, and evidence was given to the Privy Council by slave owners, slave traders and abolitionists.

Abolition was the first mass movement in British history, and in 1792 every county sent petitions to Parliament. Altogether 519 petitions were presented in that year, the largest number ever on a single subject or in a single session. Wilberforce used these petitions to exert pressure on Parliament to abolish the slave trade, and it almost worked: in 1792 the House of Commons resolved by 230 votes to 85 that the trade ought to be gradually abolished. However the very size of the numbers petitioning began to alarm Parliament. The violent struggles of the French Revolution were used by pro-slavery interests to suggest that the abolitionists were dangerous radicals (see Abolition display case, exhibit 5). In 1793 the Commons refused to revive the subject of the slave trade.

This fear of popular movements slowed the anti-slavery campaign, and not until 1807 did Parliament pass an Act abolishing Britain’s role in the slave trade. Slavery itself remained legal in British colonies until 1833, when a second Act was passed which gradually abolished slavery within the British Empire.


The captions to material used in the exhibition are given below:


Display case 1 (Profit)

1   List of Royal African Company court of assistants 1687/8. [Guildhall Library Pam 7770].

Of the 24 members of the court, Bathurst, Hedges, Ivat, Lucy, Morice (Morris) and Roberts were aldermen of the City of London; Dashwood, Moore, Turner and Wolfe were Lord Mayors.


Letter book of Edward Grace and Co, brokers and merchants of the City of London, trading mainly in slaves and oil in Gambia, Senegal and the West Indies. [GL Ms 12048/1]. The volume is open at a letter of 20 October 1767 to Day & Walsh, a firm in Antigua, about the transportation and sale of slaves.

 3  Monument to William Beckford, 1771, by John Francis Moore in Guildhall, photograph by Bedford Lemere & Co., circa 1930. [GL Photo.A 281:8]. The monument includes the text of his speech to King George III on 23 May 1770 attacking the King’s ministers.           

 Sale, by William Beckford the younger, of the Harbour Head plantation in Jamaica, 1821. [GL Ms 633]. The deed includes the name, age and “colour” of the 125 slaves included in the sale and whether each slave is “creole” or “African”.


5     Satirical dialogue between the ghosts of King Charles II and William Beckford from an unnamed London newspaper, circa 1770. [GL Noble Collection C 78]. The imagined conversation shows that some contemporaries realised the contrast between Beckford’s slave-owning wealth and his defence of City liberties.


Balance sheet for sugar imported to London from the Rosehall Estate,           

Jamaica, June 1837. [GL Ms 8614]. The profits made from imports in 1836 and 1837 from this single estate, £1817, 18 shillings, appear as “Balance due to the Proprietors this day”.



Display case 2 (Abolition)


1   John Newton’s Thoughts on the African Slave Trade, 1788, reprinted 1962 [Guildhall Library B:N564].

Originally printed in 1788 when Parliament was debating the slave trade, Newton drew on his experience as a slave-trader as well as his religious convictions to depict the horrors of the slave trade.

John Pollock’s biography of John Newton, Amazing Grace, the dramatic life-story of John Newton, 1981 [GL B:N564]. Newton is known as an evangelical Christian and abolitionist but is also famous as the author of the hymns “Amazing Grace” and “How sweet the name of Jesus sounds” along with 280 other “Olney hymns”.

Olaudah Equiano, The African: the interesting narrative of Olaudah Equiano, 1789, reprinted 1998 [Camomile Street Library 326EQU]. Equiano’s autobiography was a bestseller in Britain, Germany, America and Holland. Well written and persuasive, it has been called “the most important simple literary contribution to the campaign for abolition”.

A Very new pamphlet indeed! [GL Pam 9237]. An anonymous pamphlet of 1792 which plays on British fears of the popular uprisings in France to link slave trade abolitionists with French Jacobins. 

5     William Cowper,  Pity for Poor Africans, written 1788, published 1800.  Cowper, a poet and close friend of Newton, sent  up the economic arguments used against abolition.

Last updated November 2004

Guildhall Library Manuscripts Section