The Zong massacre was a mass killing of more than 130 enslaved African people by the crew of the British slave ship Zong over several days from 29 November 1781. The William Gregson slave-trading syndicate, based in Liverpool, owned the ship as part of the Atlantic slave trade. As was common business practice, they had taken out insurance on the lives of the enslaved Africans as cargo. According to the crew, when the ship ran low on drinking water after a series of navigational errors, the crew threw enslaved Africans overboard.

After the slaver ship reached port at Black River, Jamaica, Zongs owners made a claim to their insurers for the loss of the enslaved Africans. When the insurers refused to pay, the resulting court cases (Gregson v Gilbert (1783) 3 Doug. KB 232) held that in some circumstances, the murder of enslaved Africans was legal and that insurers could be required to pay for those who had died. The jury found for the slavers but at a subsequent appeal hearing the judges, led by Lord Chief Justice, the Earl of Mansfield, ruled against the slave-trading syndicate owners, on the grounds that new evidence suggested that the captain and crew were at fault.

Following the first trial, Olaudah Equiano, a freedman, brought news of the massacre to the attention of the anti-slavery campaigner Granville Sharp, who worked unsuccessfully to have the ship's crew prosecuted for murder. Because of the legal dispute, reports of the massacre received increased publicity, stimulating the abolitionist movement in the late 18th and early 19th centuries; the Zong events were increasingly cited as a powerful symbol of the horrors of the Middle Passage, the transoceanic route by which enslaved Africans were brought to the New World."The Zong case study", Understanding Slavery Initiative website, 2011.

The non-denominational Society for Effecting the Abolition of the Slave Trade was founded in 1787. The next year, Parliament passed the Slave Trade Act 1788, its first law regulating the slave trade, to limit the number of slaves per ship. Then, in 1791, Parliament prohibited insurance companies from reimbursing ship owners when enslaved Africans were murdered by being thrown overboard.31 Geo. 3 c. 54 "An Act to amend and continue, for limited time, several acts of Parliament for regulating shipping and the carrying of enslaved Africans in British ships from the Coast of Africa". The massacre has also inspired works of art and literature. It was remembered in London in 2007, among events to mark the bicentenary of the British Slave Trade Act 1807, which abolished British participation in the African slave trade (though stopped short of outlawing slavery). A monument to the murdered enslaved Africans on Zong was installed at Black River, Jamaica.

Zong

The ship that later became known as Zong was a square stern ship of 110 tons burthen owned by the Dutch company Middelburgsche Commercie Compagnie who in 1777 were operating it as slave ship from Middelburg, Netherlands, to deliver enslaved Africans to the Dutch colony of Surinam in South America. It was at that time named Zorg.: "TSTD [The Trans-Atlantic Slave Trade Database on CD Rom, Cambridge, 1999] (voyage nos.11210 and 11211) records the two voyages of a Dutch slaver Zorg, which is almost certainly the later Zong. This ship was owned by the Middelburgsche Commercie Compagne, a Zeeland-based slaving firm. It had made a successful slaving voyage from the Gold Coast to Surinam in 1777 (TSTD voyage no.11210) and was captured by the British on its second voyage in 1780 (TSTD voyage no.11211)."

On 10 February 1781, during the Fourth Anglo-Dutch War, the Zorg was captured by the British 18-gun brig , who took it on to Cape Coast Castle (in modern day Ghana), the regional headquarters of the Royal African Company (RAC), arriving on 26 February. In early March, the master of one of the ships there, the William, purchased Zorg on behalf of a syndicate of Liverpool merchants including Edward Wilson, George Case, James Aspinall and William, James and John Gregson. Gregson, who had served as mayor of Liverpool in 1762, had an interest in 50 slaving voyages between 1747 and 1780. By the end of his life, vessels in which Gregson had a financial stake had carried 58,000 Africans to slavery in the Americas.

Zorg, renamed Zong by its British owners, was paid for with bills of exchange, the 244 slaves already on board forming part of the transaction. Only after the ship had started its voyage was insurance obtained. Another syndicate from Liverpool underwrote the ship and its slaves for £8,000, approximately half the slaves' potential market value, with the remaining risk being borne by the owners.

Crew Zong was the first command of Luke Collingwood, formerly the surgeon on the William. While Collingwood lacked experience in navigation and command, ship's surgeons were typically involved in selecting captured Africans for purchase, so their medical expertise supported the determination of "commodity value" for a captive. If the surgeon rejected a captive, that individual suffered "commercial death", being of no value and was liable to be killed by the African traders. Sometimes these killings happened in the presence of the surgeon. It is therefore likely that Collingwood had already witnessed the mass killing of slaves. Historian Jeremy Krikler commented that this may have prepared him psychologically to condone the massacre that later took place on the Zong. Zong first mate was James Kelsall, who had also served on the William.

The vessel's only passenger, Robert Stubbs, was a former captain of slave ships. In early 1780 he was appointed by the African Committee of the Royal African Company as the governor of Anomabu, a British fortification near Cape Coast Castle in Ghana. This position made him also vice-president of the RAC council of the castle. Due to his ineptitude and enmity incurred with John Roberts, governor of the castle, Stubbs was forced out of the governorship of Anomabu by the RAC council after nine months. Witness statements gathered by the African Committee of the RAC accused him of being a semi-literate drunkard who mismanaged the slave-trading activities of the fort. Stubbs was aboard to return to Britain; Collingwood may have thought his earlier experience on slave ships would be useful.

Zong had a 17-man crew when it left Africa, which was far too small to maintain adequate sanitary conditions on the ship. Mariners willing to risk disease and rebellions on slave ships were difficult to recruit within Britain and were harder to find for a vessel captured from the Dutch off the coast of Africa. Zong was manned with remnants of the previous Dutch crew, the crew of William and with unemployed sailors hired from settlements along the African coast.

The Middle Passage When Zong sailed from Accra with 442 slaves on 18 August 1781, it had taken on more than twice the number of people that it could safely transport. In the 1780s, British-built ships typically carried 1.75 slaves per ton of the ship's capacity; on the Zong, the ratio was 4.0 per ton. A British slave ship of the period would carry around 193 slaves and it was extremely unusual for a ship of Zong relatively small size to carry so many. After taking on drinking water at São Tomé, Zong began its voyage across the Atlantic Ocean to Jamaica on 6 September 1781. On 18 or 19 November, the ship neared Tobago in the Caribbean but failed to stop there to replenish its water supplies.

It is unclear who, if anyone, was in charge of the ship at this point, as Collingwood had been gravely ill for some time. The man who would normally have replaced him, first mate James Kelsall, had been suspended from duty following an argument on 14 November. Stubbs had captained a slave ship several decades earlier and he temporarily commanded Zong during Collingwood's incapacitation but he was not a registered member of the vessel's crew. According to the historian James Walvin, the breakdown of the command structure on the ship might explain the subsequent navigational errors and the absence of checks on supplies of drinking water.

Massacre

On 27 or 28 November, the crew sighted Jamaica at a distance of but misidentified it as the French colony of Saint-Domingue on the island of Hispaniola. Zong continued on its westward course, leaving Jamaica behind. This mistake was recognised only after the ship was leeward of the island. Overcrowding, malnutrition, accidents and disease had already killed several mariners and approximately 62 Africans. Kelsall later claimed that there was only four days' water remaining on the ship when the navigational error was discovered and Jamaica was still 10 to 13 sailing days away.

If the slaves died onshore, the Liverpool ship-owners would have had no redress from their insurers. Similarly, if they died a "natural death" (as the contemporary term put it) at sea, then insurance could not be claimed. If some enslaved people were thrown overboard to save the rest of the "cargo" or the ship, then a claim could be made under "general average". (This principle holds that a captain who jettisons part of his cargo to save the rest can claim for the loss from his insurers.) The ship's insurance covered the loss of slaves at £30 per person.

On 29 November, the crew assembled to consider the proposal that some of the slaves should be thrown overboard. Kelsall later claimed that he had disagreed with the plan at first but it was soon unanimously agreed upon. On 29 November, 54 women and children were thrown through cabin windows into the sea. On 1 December, 42 male slaves were thrown overboard and 36 more followed in the next few days. Another 10, in a display of defiance at the inhumanity of the slavers, chose to commit suicide by jumping into the sea. Having heard the shrieks of the victims as they were thrown into the water, one of the captives requested that the remaining Africans be denied all food and drink rather than being thrown into the sea; the crew ignored this request. In total, 142 Africans were killed by the time the ship reached Jamaica. The account of the King's Bench trial reports that one slave managed to climb back onto the ship after being thrown into the water.

The crew claimed that the Africans had been jettisoned because the ship did not have enough water to keep them all alive for the rest of the voyage. This claim was later disputed, as the ship had of water left when it finally arrived in Jamaica on 22 December. An affidavit later made by Kelsall stated that on 1 December, when 42 slaves were killed, it rained heavily for more than a day, allowing six casks of water (sufficient for 11 days) to be collected.

Arrival at Jamaica On 22 December 1781, Zong arrived at Black River, Jamaica, with 208 slaves on board, less than half the number taken from Africa. The survivors were sold in the Jamaican slave market in January 1782, typically to labour on sugar plantations where the average lifespan of newly arrived slaves was three years. They sold for an average price of £36 per person. The Jamaican Vice-Admiralty court upheld the legality of the British capture of Zong from the Dutch and the syndicate renamed the ship Richard of Jamaica. Collingwood died three days after Zong reached Jamaica, two years before the 1783 court proceedings about the case.

Legal proceedings