Copper and Slavery

Forced labour was not uncommon in World history — Africans and Europeans had been trading goods and people across the Mediterranean for centuries — but enslavement had not been based on race. The copper industry in the eighteenth Century was intertwined with the growth of the slave trade between England and Africa and the Caribbean. West African people were kidnapped, transported to the Caribbean and sold as a commodity. The growth of the sugar industry in plantations in the Caribbean required a greater labour force.

In Bristol, the Society of Merchant Venturers (which is still in existence today) was key in the development of the slave trade. This Society was made up of wealthy local businessmen and merchants who part-owned ships, usually with an agent acting as the overall manager. The White Rock copper works in Swansea was owned by a Bristol family, the Costers from 1737. Thomas Coster (1684-1739) was a wealthy merchant and MP for Bristol, and a part-owner of at least three ships whose purpose was to carry slaves. These ships sailed from Bristol to Africa and then onwards to the Caribbean and the south-east coast of the United States between 1720 and 1740 (Evans, 2010).

The copper objects which were made at White Rock were rods, ingots and manillas, armlets which were used as currency in West Africa. These were transported by ships from Swansea to Coster’s mill works on the river Chew near Keynsham, and beaten into other products such as copper bowls which were used in the production of sugar in the Caribbean by slaves.

It has been calculated that the number of slaves transported by Bristol ships between 1698 and 1807 was half a million, which was about a fifth of the total number of slaves transported by British ships (Richardson, 1985). Ships from ports such as Liverpool and London carried the majority. No accurate figure has been made as to the amount of wealth generated to Bristol by selling slaves. 

Many UK institutions such as the Bank of England and high street banks such as Lloyds and Barclays had links with slavery. Lloyds Insurance of London insured all the ships involved in transporting slaves. Many wealthy landowners connected with slavery passed their properties to the care of the National Trust or Historic England.

The Slave Trade Act abolishing slavery was passed in England on 25th March 1807. The use of slaves was completely outlawed in the mid-1840s. The Anti-Slavery International organisation was originally formed in 1839. It still fights slavery today.


In 1837 an Act of Parliament was passed, the Slave Compensation Act, which was the world’s first major act of compensated emancipation. It authorized the Commissioners for the Reduction of the National Debt to compensate slave owners in the British colonies of the Caribbean, Mauritius, and the Cape of Good Hope to the amount of £20 million pounds for freed slaves. Based on a government census of 1st August 1834, over 40,000 awards were issued to slave owners.

As some of the payments were converted into government annuities, the awards were paid until 2015.


Evans, Chris (2010): Slave Wales. The Welsh and Atlantic Slavery 1660-1850. University of Wales Press, Cardiff.

Richardson, David (1985): The Bristol Slave Traders: A Collective Portrait. Historical Association, Bristol bha060.pdf (

Kaye, Mike (2005): 1807-2007: Over Two Hundred Years of Campaigning Against Slavery. Anti-Slavery International, London.

Bristol and the Transatlantic Slave Trade: Bristol Museums.

The Centre for the Studies of the Legacies of British Slavery: University College, London.

Huxtable, Sally-Anne, Fowler, Corinne, Kefalas, Christo, Slocombe, Emma (2020): Interim Report on the Connections between Colonialism and Properties now in the Care of the National Trust, Including Links with Historic Slavery. National Trust, Swindon.

 Wills, Mary and Dresser, Madge (2020) The Transatlantic Slave Economy and England’s Built Environment: A Research Audit. Historic England, London.’sBuiltEnvironment_AResearchAudit

The National Archives: