Prince Charles admitted that slavery has been a "dark stain" on Britain as he congratulated Barbados on becoming a Republic.

The Prince of Wales visited the Caribbean nation for the last time as its Prince as the country prepared to replace his mother, Queen Elizabeth II, as the head of state. In a major speech on the occasion, the British royal said that he was touched to be invited despite the act of severance with his family.

"The creation of this Republic offers a new beginning, but it also marks a point on a continuum – a milestone on the long road you have not only travelled, but which you have built," he addressed the attendees at National Heroes Square, where pop-star Rihanna was also present, reports The Mirror.

The heir apparent to the British throne went on to acknowledge the barbaric transatlantic slave trade as he said, "From the darkest days of our past, and the appalling atrocity of slavery, which forever stains our history, the people of this island forged their path with extraordinary fortitude."

"Emancipation, self-government and Independence were your way-points. Freedom, justice and self-determination have been your guides," the 73-year-old added. The Queen also sent her "warmest good wishes" on the occasion, praising the nation of Barbados which holds a "special place" in her heart for "its vibrant culture, its sporting prowess, and its natural beauty."

The British monarch had been Barbados's head of state since it gained its independence in 1966, over three centuries after an English ship claimed the island for King James I in 1625. The nation, which has become a Republic after 55 years of its independence, received 600,000 enslaved Africans between 1627 and 1833, who worked in the sugar plantations and earned fortunes for their English owners. Buckingham Palace had previously said the issue of republicanism was a matter for the people of Barbados to decide, and that the same applies to the other 15 realms where the Queen is head of state such as Jamaica, Australia, and Canada.

A senior palace source said that Prince Charles felt honoured that he was involved in the celebrations of the country abolishing the monarchy, and wanted to use the opportunity to "further recognise that the profound injustice of the legacy of the slave trade could never be forgotten."

Prince Charles
President-elect Sandra Mason (2L), Prime Minister Mia Amor Mottley (3R) and Prince Charles stand on parade at the airport in Barbados ahead of the country's transition to becoming a republic Randy Brooks/AFP