Monuments matter. That’s why the current debate about statues is important. They are material expressions of memory in the public realm. Some are potent national symbols of celebration or commemoration, such as the statue of Nelson in Trafalgar Square or the Cenotaph war memorial in Whitehall. Less common are monuments of national contrition. The Holocaust memorial in Berlin is one of the best known.

In the UK, there have been calls for several years for a national monument of atonement for the victims of transatlantic slavery. The case is compelling – our nation was by far the biggest trader in slaves shipped to North America and the Caribbean.

It was directly responsible for the forced and brutal migration of more than three million enslaved Africans across the north Atlantic between the 17th and 19th centuries. Half a million died on the journey.

Yet this reality remains largely hidden from history. Our national story has been much less focused on contrition for our responsibility in the formation of the slave trade than on celebration of its abolition. We cannot continue to gloss over our past.

Hiding slavery behind philanthropy

Redressing this imbalance underpins the welcome initiatives by the National Trust and other cultural custodians to reveal the hidden links between our heritage and this trade. A failure to acknowledge such culpability was the backdrop to the toppling of the Bristol statue of Edward Colston. This monument celebrated his philanthropy but hid his leading role in the slave trading Royal African Company in the 1680s.

When the Black Lives Matter movement toppled the Bristol monument in June last year, it beamed a spotlight on this murky national history. Yet the subsequent debate has wandered off into disputes over the statues of little known philanthropists, who were relatively minor figures in the Royal African Company. Surprisingly, the crucial central figure in England’s early conquest of the global slave trade has escaped unnoticed.

The Royal African Company secured its dominant role in the slave trade under James Stuart, Duke of York, (who went on to have a short-lived reign as King James II), who acted as its governor for 16 years. Under his leadership, the company more than doubled a minority English share to achieve an overwhelming 74% of the market by outcompeting the Dutch and French.

James II commanded the navy, as lord high admiral, to support the company. New York was named in his honour, following the capture of New Amsterdam. His initials DY were branded on slaves to mark his power and property. The scale of the Royal African Company’s trade was subsequently overshadowed by the market entry of many other slave traders in the 18th century. Nevertheless, its heyday under James was a key historic moment when the Crown actively moved to assert the global leadership of England over the slave economy.

James II is commemorated by a notable statue in our most celebrated national public space, Trafalgar Square, on the lawn in front of the National Gallery. Finely sculpted by Grinling Gibbons, and initially erected in 1686 behind the Whitehall Banqueting House, it was lucky to survive the Glorious Revolution. Less fortunate was a sister statue of him in Newcastle that was thrown into the Tyne by a mob in May 1689.

The London statue ended up being moved from site to site over the years. The decision to locate it in Trafalgar Square in 1947 was met with vocal opposition. A contributor to The Times in the 1950s called it a statue of an “apostle of chicanery”, which should be “dropped into the Thames” but the controversy never touched upon his historic role in slavery. Paradoxically, the internationally known location of his statue has created an extraordinary opportunity to confront his slave-trading legacy.

Earlier this year, the National Gallery announced a competition to redesign its Sainsbury Wing and to ‘reimagine the external public realm’ at its doorstep. At the heart of this ‘realm’ is the statue of James II.

This is an unmissable moment to share this setting with an imaginative counter-monument of national contrition for our central role in the slave trade. This does not mean the removal of the statue. Quite the opposite. The statue’s very presence is what makes it such a suitable and sensitive site. But it needs a striking and visible counter-monument to tell a national story which is inclusive and honest.

Here is an opportunity to show that the country is ready to acknowledge the darker side of its colonial past. It begs to be an exemplary mission for the London Mayor’s new Commission for Diversity in the Public Realm. We need a powerful cultural counterpoint that speaks directly to this statue of James II as a pivotal creator of the slave trade. A statue of ‘the unknown slave’ could be one option but who can guess what might arise from the public’s imaginations if given the chance.

No doubt the right-wing, anti-woke culture warriors will scoff. Yet this proposal clearly fits the new official government policy to ‘retain and explain’ a contested statue. A meaningful effort ‘to explain’ deserves an original and inspiring material tribute to the black lives devastated by slavery. It demands a stature and presence with far greater visual impact than a textual plaque. Will the National Gallery step up to the challenge? And will Downing Street and the Palace speak out in support?