In late 1781, the British slave ship Zong, bound for Jamaica, navigated off course due to navigational error. Fearing a shortage of water and facing outbreaks of disease among the captive Africans, the ship's crew made a horrifying decision. Under maritime law at the time, if enslaved people died on land or from natural causes aboard the ship, the vessel's owners bore the financial loss.
However, if cargo was thrown overboard to save the ship and remaining cargo—a legal concept known as general average—the loss would be covered by insurer underwriters. Over three days, the crew threw 133 enslaved men, women, and children into the ocean. Upon returning to Britain, the ship's owners, Gregson syndicate, filed an insurance claim for the value of the thrown-overboard slaves.
The insurers refused to pay, leading to the landmark court case Gregson v. Gilbert in 1783. Remarkably, the trial was conducted strictly as a commercial dispute over property loss.
Lord Chief Justice Mansfield presided over the case, declaring that the law treated the victims no differently than horses or goods thrown overboard during a storm. Though the underwriters initially lost and appealed, the public outrage generated by the trial details catalyzed the British abolitionist movement. Activists like Granville Sharp sought criminal charges for murder, but Solicitor General John Lee argued that it was absurd to charge men with murder for throwing cargo into the sea.
The legal framing of human life as insurable property exposed the extreme dehumanization codified in 18th-century maritime law, turning a cold commercial contract into a pivotal rallying point for anti-slavery campaigners.