Global Threads research traces links between Peterloo and Caribbean slavery

Global Threads research reported on 10 October 2026 traces links between the 1819 Peterloo massacre in Manchester and the enslavement of Africans in the Caribbean. By examining a militia commander’s family finances, a newspaper backer’s plantation interests and an abolitionist’s response to the killings, the public-history project adds a transatlantic account to a landmark struggle for political representation.

The cases concern Hugh Hornby Birley, Sir George Philips and Robert Wedderburn. They do not show that Manchester workers and enslaved Caribbean people lived under the same conditions. The project’s argument, as reported by the Guardian, is that their struggles were connected through the people and economic networks that held power across the Atlantic.

What happened at Peterloo in 1819

About 60,000 people gathered at St Peter’s Field on 16 August 1819 to demand political representation, according to the Guardian’s account. The Manchester and Salford Yeomanry charged the crowd. The report describes protesters being shot and trampled to death, and says authorities blamed the protesters afterward.

The demand for representation came amid severe limits on voting and pressure on workers’ living costs. The Guardian says only about 10% of men in Britain could vote in 1819. It also describes workers struggling to afford bread while landowners benefited from tariffs on imported grain under the Corn Laws. Those conditions help explain the protest, while remaining distinct from the legal ownership and forced labour imposed on enslaved Africans.

How Birley’s family was linked to plantation wealth

Citing the Slave Voyages database, Sinclair says Daniel Backhouse co-owned 103 slave-trading voyages from Liverpool between 1773 and 1807, estimated to have trafficked more than 27,000 African captives. The study says three Backhouse-linked voyages brought enslaved people to St Lucia. A partnership involving Backhouse financed and profited from the Rabot sugar estate there, where the research records 62 enslaved people in 1815.

The 1815 Rabot register offers a closer view of those figures. According to Sinclair’s study, nine residents were African-born: two recorded as from ‘Guinea’ and seven from Cape Verde. It says 19 people primarily worked with hoes in sugar-cane fields. The records describe people whose labour generated plantation income, rather than an abstract connection between two places.

The financial trail continued through inheritance. Sinclair says Backhouse’s 1812 will placed Caribbean property and plantations in trust, with Birley’s younger brother John among the trustees. The study says John Hornby later claimed government compensation for the Rabot estate as heir to Backhouse’s financial interest. It values the 46 people still held there at £1,299 in 1838 and says the freed people received no compensation. These are documented links within a family and business network; the records do not establish a personal connection between every Manchester cotton worker and a plantation.

Why Philips and Wedderburn matter to the account

The Guardian reports that Global Threads also examined Sir George Philips, who helped fund the Manchester Guardian after Peterloo. Philips owned the Success plantation in Jamaica, the report says. His case places a supporter of liberal political change in Manchester alongside direct financial involvement in Caribbean enslavement. Birley and Philips were both members of the Portico Library, which the report describes as a meeting point for the city’s business elite.

Wedderburn supplied a contemporary argument connecting the struggles. The Guardian identifies him as a Jamaican-born abolitionist preacher whose mother was enslaved and whose father owned a plantation. In September 1819, he challenged the official account of Peterloo, calling it ‘an act of murder … committed by the magistrates and yeoman’. The report says he had long argued that Africans and English labourers were denied rights by the same forces. It also says he was in prison at the time of the massacre, accused of inciting enslaved people to kill their enslavers.

What the research establishes

The Guardian presents these three lives as connected routes into the history of Peterloo, while Sinclair’s earlier Portico study sets out the archival trail behind the Birley family case. The research resource dates from 2025; the new development is the Guardian’s 10 October account drawing the cases together. The available accounts support specific links among Manchester institutions, political figures and Caribbean plantations, and a contemporary abolitionist’s interpretation of Peterloo. They do not establish that the experiences of Manchester workers and enslaved Africans were equivalent.