The King hailed the Windrush generation’s “immeasurable” impact as he marked the 75th anniversary of the first crossing from the Caribbean.
Charles said those who had come had made a “profound and permanent contribution to British life”.
HMT Empire Windrush arrived at Tilbury Docks in Essex on June 22, 1948, bringing nearly 500 people from the Caribbean. They were the first of thousands encouraged to migrate and help fill labour shortages in the armed forces, industry and NHS.
The anniversary was being marked with events across Britain including a national commemoration service at Southwark Cathedral, with the King attending an event for young people at St George’s Chapel, Windsor.
Charles sat among a congregation of 300 specially invited guests including young people from schools across England, dignitaries and representatives from a number of charities and community projects.
Reverend Rose Hudson-Wilkin, the Bishop of Dover, told the congregation at the service that they had gathered at a time of particular “poignancy” because it was a day of celebration and thanksgiving for the hardworking good citizens she refers to as the “Windrush pioneers”.
She told the congregation: “They are pioneers who paved the way for generations who came after them, not merely to survive but to thrive.
“The significant contributions made by the Windrush pioneers in the United Kingdom to the National Health Service, the transport network, to the arts, sports, religion and life is second to none.”
Charles has said it is “crucially important” to recognise the “immeasurable” difference the Windrush generation has made to Britain.
His comments were made in the foreword of a book which accompanies a display of portraits that celebrate the Windrush generation in the week marking the anniversary of the crossing.
He added: “Those pioneers, who arrived in a land they had learned about from afar, left behind all that was familiar to them.
“Many served with distinction in the British Armed Forces during the Second World War, just as their fathers and grandfathers had in the First World War.
“Once in Britain, they worked hard, offering their skills to rebuild a country during peacetime and seeking opportunities to forge a better future for themselves and their families.
“When they arrived on our shores with little more than what they were able to carry with them, few could hardly have imagined then how they, and those that followed them, would make such a profound and permanent contribution to British life.”
Last week, Charles hosted a Buckingham Palace reception where he met the 10 individuals whose faces have been immortalised in paint, and was given a special preview of the artworks marking the 75th anniversary.
Representatives from the Prince's Trust, the Prince’s Foundation, Project Zero and the Amos bursary were among those who attended the service.
Mayor of London Sadiq Khan said that the milestone could not be marked without acknowledging the “disgraceful treatment” some had endured and the scandal that saw immigrants wrongly deported.
Five years ago the Home Office apologised for not properly recording the details of people granted permission to stay in the UK and destroying the landing cards of Windrush migrants.
At least 83 people who arrived before 1973 were wrongly deported and many more were unable to work and denied access to benefits and healthcare.
Mr Khan said: “It’s important to celebrate the pivotal role the Windrush generation and their descendants have played in helping to make our city the greatest in the world.
“From those working for the NHS and Transport for London, to the activists and creatives who’ve shaped our culture, their incredible contribution must always be valued.”
A £1 million campaign has been set to recover the 1.5 tonne anchor from the Windrush, which sank off Algeria in 1954. The Windrush Anchor Foundation wants to display it as a memorial.
