Study Links Caribbean Slavery to Peterloo Massacre and Manchester Elite

On 16 August 1819, 60,000 people converged in the centre of Manchester to campaign for political representation. Only 10% of men in Britain could vote, and while landowners were enriched by tariffs placed on foreign grain by the Corn Laws, workers could barely afford bread. The protest at St Peter's Field ended in tragedy when the Manchester and Salford Yeomanry, a militia of Tory businessmen, charged the crowd; peaceful protesters were shot and trampled to death. In the aftermath, the authorities blamed protesters, but Robert Wedderburn, a Jamaican-born Unitarian preacher and Black abolitionist in London, was quick to challenge the official narrative. In September 1819, at a meeting at his Soho chapel, he described Peterloo as 'an act of murder … committed by the magistrates and yeoman'. In his preaching and writings, Wedderburn had long argued that Africans and English labourers were being denied by the same forces.

Global Threads said its research drew together 'just three of the thousands of threads connecting Peterloo with Africa and the Americas'. It examined Hugh Hornby Birley, the yeomanry commander who led the fatal charge on the crowd, and Sir George Philips, who helped fund the Manchester Guardian as a liberal reaction to Peterloo. Both were members of the Portico Library, Manchester's historic members' library, which in the 19th century was a centre of information exchange for the city's business elite. The Global Threads project is part of research into the history of the Portico, which stands a few yards from where the Peterloo massacre took place.

The study found Birley's family fortune was intimately linked with transatlantic enslavement. Ella Sinclair, writing for Global Threads, found Birley's family business financially benefited from the estate of Daniel Backhouse, an enslaver who funded and profited from 103 voyages that set out from Liverpool between 1773 and 1807, trafficking more than 27,000 Africans. In the late 18th century, three of those voyages exported people to St Lucia, where Backhouse's company funded and profited from the Rabot sugar estate. Early 19th-century records reveal that workers there included families trafficked from Guinea and Cape Verde. After the emancipation of enslaved Africans in the British empire in the 1830s, the Birley family supported the enslaving US Confederacy, which was integral to their cotton interests. Sinclair found Birley was closely involved with the development of Manchester institutions, including 'the Liverpool and Manchester Railway – designed to more easily transport slave-produced cotton'.

Philips, meanwhile, reflected the contradictions of 19th-century liberal politics. While he helped fund the Manchester Guardian as a liberal reaction to Peterloo, he was personally invested in the exploitation of enslaved Africans in the Caribbean as owner of the Success plantation in Hanover, Jamaica.

Wedderburn's family was also embedded in the plantation economy. His uncle, John Wedderburn, owned the Blackheath, Blackness, Bluecastle and Glen Islay plantations in Westmoreland, Jamaica. Workers on those plantations included people trafficked from Old Calabar, in modern-day Nigeria, to Montego Bay in 1773, on a ship carrying textiles woven in Manchester. Robert Wedderburn's mother was an enslaved woman called Rosanne.

Global Threads said the leaders of each wing of Manchester's elite 'owed their positions and power to their family and business activities drawing on colonialism and slavery'. It added: 'They actively described the system they had created as a transatlantic one. It was not just profit that connected Peterloo … Birley and his reactionary colleagues brought colonial-style coercion more akin to the putting down of uprisings of enslaved people, working people themselves were connected to transatlantic people and places, and slavery hung like a spectre over the Mancunian struggles for justice and equality.'