One autumn day in 1786, an unexpected parcel arrived at Carlton House, the London residence of George, Prince of Wales. The sender was Quobna Ottobah Cugoano, a free Black man living in London, one of roughly 4,000 people of African descent in the city at the time. Inside the package were pamphlets describing the horrors of the transatlantic slave trade and the brutal treatment of enslaved people in Britain’s Caribbean colonies. The accompanying letter, signed “John Stuart,” Cugoano’s alias, urged the heir to the British throne to read the “little tracts” enclosed and to “consider the case of the poor Africans who are most barbarously captured and unlawfully carried away from their own country”.

Africans, Cugoano warned, were treated “in a more unjust and inhuman manner than ever known among any of the barbarous nations in the world”.

At the time, Cugoano was employed as a domestic servant by the fashionable painters Maria and Richard Cosway, whose home stood just two blocks from Carlton House. Richard Cosway had recently been appointed principal painter to the Prince of Wales, and his residence at Schomberg House on Pall Mall had become a gathering place for artists, aristocrats and politicians. Weekly salons and concerts drew members of the highest society – events sanctioned by the prince himself. Through this employment, Cugoano gained something rare for a former enslaved man: regular, direct proximity to Britain’s elite and to the royal family.

Cugoano used it to full advantage.

Schomberg House was a monument to social ambition. Its grand drawing rooms opened on to gardens that stretched almost to the edge of Carlton House’s own grounds. Cosway, newly elevated by royal favour, filled his home with lavish furnishings and dressed his Black servant in flamboyant bespoke livery – crimson silk or velvet trimmed with lace and gold buttons. In Georgian Britain, Black servants were fashionable accessories, visible symbols of wealth and imperial reach. Kings, princes, admirals and aristocrats employed them. In portraits of elite families, Black attendants hovered at the margins, holding trays, opening doors, silent witnesses to English life.

Cugoano, however, was not silent.

Born around 1757 in a Fante village on the coast of what is now Ghana, his childhood ended abruptly when slave traders raided his community. At 13, he was kidnapped, marched in chains to the coast, and forced onboard a slave ship. He later described the Atlantic crossing as a passage of terror, a “state of horror and slavery”. The ship delivered him to Grenada, where he was sold and forced to labour in a plantation slave gang.

After nearly two years, his enslaver brought him to England in late 1772 – just months after Lord Mansfield’s famous ruling in the Somerset case, which declared that enslavers could not forcibly remove enslaved people from England. Though narrow in legal scope, the decision sent shockwaves across Britain. Many believed, mistakenly but hopefully, that touching English soil meant freedom.

Cugoano soon claimed his liberty. Whether he fled or was cast out is unclear, but freedom in London was precarious. Formerly enslaved people were vulnerable to kidnapping and resale. On the advice of “some good people”, Cugoano was baptised at St James’s Church, Piccadilly, adopting the name John Stuart so that he “might not be carried away and sold again”. An Anglo-Christian name did not guarantee safety, but it offered camouflage.

Over the next decade, Cugoano learned to read and write, became a devout Anglican, and embedded himself in London’s small but vibrant free Black community. By the mid-1780s, he had joined a group of Black activists calling themselves the Sons of Africa – former enslaved men, sailors and Black loyalists who had supported Britain and George III during the American Revolutionary War. Together, they wrote letters, published pamphlets, lobbied MPs and challenged the illegal seizure of free Black people in Britain.

One such intervention saved a man named Harry Demaine, who had been recaptured by a Jamaican planter and dragged onboard a ship bound for the Caribbean. Acting swiftly, Cugoano and another Son of Africa alerted the abolitionist lawyer Granville Sharp, who secured Demaine’s release just minutes before the ship sailed. Demaine later said that he had planned to jump into the sea rather than be returned to slavery.

These were acts of resistance carried out in the shadow of royal power.

Cugoano understood that abolishing the slave trade would require more than rescue missions. It would require the support – or at least the acquiescence – of the monarchy. For generations, enslaved people across the British empire had petitioned the king, believing him to be a distant source of justice, capable of overriding colonial cruelty. Abolitionists, too, recognised the symbolic power of royal endorsement.

From his post at Schomberg House, Cugoano watched the Prince of Wales up close. He observed his vanity, his appetite for praise, his obsession with legacy. And so, when Cugoano finally wrote to him, he tailored his appeal accordingly.

If the prince used his future power to end the “iniquitous traffic of buying and selling men”, Cugoano promised, his name would “resound with applause from shore to shore” and be held “in the highest esteem throughout the annals of time”. It was a calculated appeal to ambition: history, glory, immortality.

The following year, Cugoano sent the prince a copy of his newly published book, Thoughts and Sentiments on the Evil and Wicked Traffic of the Slavery and Commerce of the Human Species. It was the first anti-slavery treatise written by a formerly enslaved African in Britain. He reminded the prince that enslaved Africans had no ambassadors, no formal representatives. Their only hope was to “lay our case at the feet of your Highness”.

The Prince of Wales kept the book, and it still sits in the royal collection. He did nothing else.

Cugoano also sent his book to George III, adopting a different strategy. To the king – head of the Church of England – he appealed to Christian duty and moral responsibility. Justice and humanity, he wrote, were the motives behind his work, and surely a sovereign would be pleased to support the natural liberties of men.

Yet Cugoano’s book did not flatter monarchy. It indicted it.

For centuries, he argued, European kings had sanctioned, defended and profited from the buying and selling of African captives. In Britain, the transatlantic slave trade had not emerged accidentally or at the margins of power. It was formally established by royal authority when Charles II granted a monopoly charter to the Royal African Company. Successive monarchs and their families benefited from that investment in slaving. To claim royal innocence now, Cugoano insisted, was a fiction.

The king and his relations occupied the most exalted position in British society. Yet as the descendants and beneficiaries of England’s first major investors in the slave trade, George III and the royal family set a corrupt example for the nation to follow. Monarchy did not merely preside over slavery; it normalised and legitimised it.

Christian justifications for bondage, Cugoano continued, collapsed under scrutiny. Enslavers routinely denied religious instruction to the people they claimed to civilise. Plantation slavery was not benevolent guardianship but a regime of terror. If kings and nations possessed the power to prevent such injustice and refused to act, how could they expect God’s favour – or escape his judgment?

This was no polite appeal. It was a warning.

The British government, Cugoano wrote, continued to “traffic in the human species”, a crime “established by royal authority” and still supported and carried on by a Christian government.

Responsibility did not rest solely with slave traders or planters but with the nation as a whole – and most heavily with its sovereign. Kings and “great men”, he argued, were “more particularly guilty”.

Unless George III intervened to end Britain’s slave trade, he said, divine retribution would follow.

White abolitionists carefully avoided such language. They courted royal goodwill, emphasising mercy rather than blame. Cugoano refused. He had no intention of holding back his disgust for the British people and the sovereign who had profited from his enslavement and ignored the ongoing anguish and death of countless Africans. Cugoano demanded immediate abolition, universal emancipation, and the political inclusion of Black people as free subjects – positions most Britons, abolitionist or not, considered dangerously radical.

“But why,” he asked, “should total abolition, and an universal emancipation of slaves, and the enfranchisement of all the Black people employed in the culture of the colonies taking place as it ought to do, and without any hesitation, or delay for a moment, even though it might have some seeming appearance of loss either to government or to individuals, be feared at all?”

Few listened, and Cugoano’s book initially attracted little attention. Yet his ideas did not disappear.

By 1791, an abridged edition gained influential subscribers – artists, aristocrats, politicians. The movement he helped build gathered force. Abolition spread from pamphlets to parliament, from London drawing rooms to the far edges of Britain’s slave empire.

Cugoano himself vanished from the historical record soon after, his final years unknown. But one trace remains: the book he placed in royal hands, the arguments laid at the feet of a future king, and the silence that followed.

The monarchy had been confronted – directly, unmistakably – by a man who had survived its slave system and refused to thank it for his freedom. The opportunity for moral leadership was offered. It was declined.

That silence would echo for generations.