Britain's Prince Charles expressed his "personal sorrow" over the suffering of slavery and its "enduring impact" on Friday.
Speaking at the opening of the Commonwealth Heads of Government Meeting in Kigali, Rwanda, the Prince of Wales, who is representing Queen Elizabeth II, said the past faults should be acknowledged for a common future.
"To unlock the power of our common future, we must also acknowledge the wrongs which have shaped our past," he said. "Many of those wrongs belong to an earlier age with different, and in some ways, lesser values."
The prince said he wants to acknowledge "that the roots of our contemporary association run deep into the most painful period of our history."
"I cannot describe the depths of my personal sorrow at the suffering of so many, as I continue to deepen my own understanding of slavery's enduring impact," he added.
During the historic Transatlantic Slave Trade, British merchant supported by the state transported and enslaved more than 3 million people from Africa, a policy which had not been abolished until 1807.
Speaking on the commonwealth countries' relationship with the UK's monarchy, the prince said their constitutional link with the Buckingham Palace is "a matter for each member country to decide."
He said: "The Commonwealth contains within it countries that have had constitutional relationships with my family, some that continue to do so, and increasingly those that have had none.
"I want to say clearly, as I have said before, that each member's constitutional arrangement, as republic or monarchy, is purely a matter for each member country to decide. The benefit of long life brings me the experience that arrangements such as these can change, calmly and without rancor.
"As I said in Barbados last November, we should never forget the things which do not change: the close and trusted partnership between Commonwealth members; our common values and shared goals; and, perhaps most importantly, the strong and enduring connections between the peoples of the Commonwealth which strengthen us all."
Prince Charles' comments came after recent reactions from some Commonwealth countries such as Jamaica and Australia, where Queen Elizabeth II is the head of state. During recent royal visit to Jamaica, the members of royal family were given a cold reception, as the discussion on transitioning the country's system from monarchy to republic.
The Queen who recently celebrated her 70th year on the throne is the head of state of Australia, Canada, New Zealand, Antigua and Barbuda, The Bahamas, Belize, Grenada, Jamaica, Papua New Guinea, Saint Lucia, Solomon Islands, St. Kitts and Nevis, and St. Vincent and the Grenadines.
