A newly identified portrait of one of Britain's forgotten Black war heroes is set to rewrite part of the country's military history.

The National Army Museum in London has revealed that a rare 1821 painting, long shrouded in mystery, depicts Pte Thomas James, a Black soldier who fought valiantly in the Napoleonic wars and was among just nine known Black recipients of the Waterloo Medal, the first British medal awarded to soldiers regardless of rank, reports The Guardian.

For centuries, James's story went untold. But after months of research, the museum has identified him as the likely subject of an "extraordinarily rare" portrait painted by Thomas Phillips, whose more typical sitters were Georgian luminaries such as the Duke of Wellington and Lord Byron.

The rediscovered painting will go on public display this Tuesday at the museum's "Army at Home" gallery in Chelsea.

It will be placed on permanent display to highlight the service of James and other Black soldiers during the Napoleonic wars.

"There's this misconception that there weren't any Black soldiers at Waterloo," said Anna Lavelle, the museum's art curator.

"That's not the fault of the public; it's not been in the historical discourse. And yet Thomas James is one of many."

Lavelle said James's courage and commitment deserve far greater recognition.

"He was willing to get hurt and put his life at risk for other people in his regiment," she said.

Born around 1789 in Montserrat in the West Indies, James is believed to have begun life enslaved. Details of his early years remain scarce, but by the time he enlisted in 1809, he had made his way to Sussex, where slavery had been abolished.

There, he described himself simply as "a servant." Despite his humble beginnings and illiteracy, James would go on to earn distinction as a percussionist in the 18th Light Dragoons.

His bravery during the Napoleonic wars earned him the Waterloo Medal. He was commended after being severely wounded while defending his officers' belongings from a group of Prussian deserters attempting to loot their camp.

"There were about 20 soldiers who were looking after the officers' baggage, but James was the only one noted to have been severely wounded," Lavelle said.

"He obviously put up a really good fight – a spirited defence – which I think says a lot about his character and his sense of camaraderie."

She added that James's officers must have trusted him deeply to guard their possessions, which likely included money, jewellery, and mess silver.

"I think he was brave foremost, and honourable as well."

The portrait shows James wearing a bright white cavalry uniform and holding a pair of cymbals, reflecting his flamboyant role in the regimental band.

"Bandsmen would swing cymbals under their legs, flip them up into the air, catch them and clang them together loudly," Lavelle explained.

"It would have been quite a theatrical, high-energy performance, and taken a lot of skill."

Options for Black men in Georgian England were limited, and men who did not wish to be servants often, like James, enlisted in the army as military musicians, she said.

"Black soldiers wore the same uniform and were paid the same wages and pension as their white counterparts – and in the army hierarchy, a Black soldier and a white soldier of the same rank have to treat each other equally," Lavelle noted.

Black bandsmen were so sought after for regimental bands that they knew they would find a "small community" of other soldiers of colour within the army, she said, and when their regiments disbanded, Black soldiers would "overwhelmingly re-enlist".

The National Army Museum acquired the painting last year for £30,000, initially unaware of either the sitter's identity or the artist's hand.

"We just had a hunch it was special," Lavelle recalled.

Through a combination of archival research, medal records, and visual clues, including the uniform details and the presence of cymbals, she mentioned that the portrait most likely depicted James.

She believes the painting was commissioned by James's officers in recognition of his courage. "This portrait would have been expensive – it's not something James, or any other private in the army, would have been able to pay for themselves," she said.

Portraits of known Black British soldiers from this era are almost nonexistent; Lavelle knows of only two others in existence from the period.

"This is a portrait which can help us to tell the story of Black bandsmen in general and the important role they played in history."

The painting shows James adorned with a ring and gazing calmly at the viewer, his posture relaxed yet assured. "He comes across in the painting as quietly confident – a soldier who is dignified and has a real sense of pride," Lavelle said.

London museum / Waterloo veteran