The theft of a plaque in Hampshire that told the little-known story of African-Caribbean prisoners in 18th-century Britain reflects the enduring racism that has fuelled centuries of atrocities against Black and Indigenous Caribbean people, their descendants say.

Drummer Ronald Raymond McDonald was part of a delegation that travelled from Belize and elsewhere to Portchester Castle last week to honour their ancestors: 2,500 men, women and children transported to Britain as prisoners of war in 1796.

McDonald, whose Garifuna ancestors from St Vincent and the Grenadines were among the prisoners, said he was heartbroken to learn that the plaque had been stolen and a nearby bench vandalised with hateful graffiti.

“Why would somebody do something like that when people are simply honouring their ancestors … It’s very sad,” he said.

The plaque, installed at the castle, commemorated the more than 2,000 prisoners held there, marking an extraordinary chapter of Black British history: one of the largest known arrivals of African-Caribbean people in Britain before the Windrush era.

The unveiling was part of a ceremony organised by the St Vincent and the Grenadines 2nd Generation (SV2G), in partnership with the University of Warwick and English Heritage, and was attended by Caribbean communities, diplomats, researchers and heritage organisations.

But days later, English Heritage staff discovered the plaque was missing. They said a padlock to one of the castle gates had been removed and the incident had been reported to police.

Garifuna advocate Princess Eulogia said the theft reflected “a spirit of racism that haunts generation after generation and hides in plain sight”. It was time, she said, to recognise that “we are all connected” and to end the hate.

Queen Mother Chief Freda Paulino-Sideroff, who is Garifuna and had travelled to the UK for the ceremony, was returning home to the US when she learned of the theft.

“Hate will never define who we are as a people. We are resilient survivors of our ancestors who have endured,” she said. In the 1700s, her Garifuna ancestors were expelled from St Vincent by British forces and left to perish on the barren island of Baliceaux as Britain sought to crush decades of resistance to colonisation.

Emilio ‘Sásamu’ Thomas, a Garifuna cultural ambassador who also travelled from Belize for the ceremony, echoed Paulino-Sideroff’s defiance, saying Garifuna people would not allow themselves to be victimised. His message to the perpetrators, he said, was: “Whatever pain that they are experiencing, we’re here to help them to relieve that pain.”

The missing plaque was meant to honour the prisoners, whose story, researchers say, had been largely lost to history. They came from a coalition that included formerly enslaved Africans, Caribbean-born people, Indigenous people and French soldiers who fought against British control of St Lucia, St Vincent and the Grenadines and Grenada. Their defeat and removal helped strengthen British rule in the region.

It was unveiled on 9 October, exactly 230 years after one of the ships carrying the prisoners was wrecked at Rapparee Cove in Devon, with many of those on board losing their lives.

Iona Keen of English Heritage called the removal an act of vandalism, while University of Warwick professor Katherine Astbury said the plaque was intended to provide a visible memorial of the prisoners, and a reminder of “an important, forgotten part of Caribbean history”.

The incident comes during Black History Month and amid renewed debate over slavery reparations. Campaigner and author Sir Patrick Vernon said vandalism of memorials representing Black British history had occurred repeatedly over decades, citing damage to other memorials.

He described the theft as symbolic of an “ongoing battle and the legacy of enslavement”.

Jacqueline Roberts, SV2G chief executive, said the theft could not erase history, and stressed the importance of continuing research to uncover more hidden stories. “Our history is intertwined with British history,” she said. “It’s important to understand that part of our journey, because it is part of the complexity of our identity, and affects our sense of belonging.”

Anthony Severin, St Lucia’s high commissioner and chair of the Caribbean community diplomatic caucus in the UK, described the theft as a “desecration of the memory and spirit of our commemorated ancestors”. He pledged that the plaque “whether returned or replaced, will remain affixed to the walls of Portchester Castle”.