King Charles III has hailed the Windrush generation’s “immeasurable” impact, 75 years after the first crossing from the Caribbean.
He will be among those at a service at Windsor Castle which along with other events will mark the anniversary.
Those who came to the UK had made a “profound and permanent contribution to British life”, he said.
It comes after it emerged that many Caribbean migrants were wrongly threatened with deportation.
Almost 500 people stepped off the HMT Empire Windrush at Tilbury Docks in Essex on 22 June, 1948, the first of thousands encouraged to migrate and help fill labour shortages in the armed forces, industry and NHS.
As part of the anniversary, in 2022 the King commissioned 10 portraits of some members of the Windrush generation. They will go on public display for the first time at the Palace of Holyrood house in Edinburgh.
Writing in a book accompanying the artworks, the King said: “Though drawn from different parts of the world, they collectively enrich the fabric of our national life and the remarkable tapestry of the Commonwealth.”
He said it was “crucially important that we should truly see and hear these pioneers… and those who followed over the decades to recognise and celebrate the immeasurable difference that they, their children and their grandchildren have made to this country”.
Events set to be held on Thursday include a national service at Southwark Cathedral, and a procession through Brixton, an area of London closely associated with the Windrush generation.
There will be performances at the Port of Tilbury, the Windrush flag will be flown over public buildings, and the King will meet 300 young people at a service in St George’s Chapel, Windsor.
A £1 million fundraising effort is under way to recover the anchor from the HMT Empire Windrush and put it on public display. The ship sank off the coast of Algeria in 1954.
In 2018, it emerged some members of the Windrush generation and their descendants were facing deportation and denied access to public services because their right to live here had not been properly recorded by the government decades before.
Then-home secretary Amber Rudd apologised after a scathing report published in 2020 found it had been “foreseeable and avoidable” and that victims were let down by “systemic operational failings”.
As of last month, £75 million in compensation had been offered to those impacted, with £62.7 million of that paid out, analysis by the PA News agency showed.
But the Home Office has continued to face criticism over the handling of compensation applications.
Amelia Gentleman, a Guardian journalist who exposed the scandal, told Radio 4’s Today programme: “The anniversary remains soured by the ongoing failings of the Home Office.”
She added the 44-page form involved in claiming compensation was too complicated.
Home Secretary Suella Braverman has resisted calls for the programme to be moved out of Home Office control and the department has insisted it is “absolutely committed to righting the wrongs of the Windrush scandal”.
Meanwhile, the BBC has uncovered evidence that hundreds of long-term sick and mentally ill people were sent back to the Caribbean after arriving in Britain.