The Prince of Wales has told Commonwealth leaders the potential of the family of the nations for good cannot be realised until we all “acknowledge the wrongs which have shaped our past”.

Charles described how he was on a personal journey of discovery and was continuing to “deepen my own understanding of slavery’s enduring impact”, in a speech at the opening of a Commonwealth summit in Rwanda.

He recognised the roots of the family of nations “run deep into the most painful period of our history” and acknowledging the wrongs of the past was a “conversation whose time has come”.

But there was no apology from the heir to the throne for the royal family’s involvement in the transportation and selling of people for profit.

For centuries, successive monarchs and other royals participated in the trade, either supporting and facilitating the activity or making money from it.

Charles told the gathering of prime ministers and presidents, who included Boris Johnson, he could not “describe the depths of my personal sorrow at the suffering of so many” during slavery.

The prince is representing the Queen at the Commonwealth Heads of Government Meeting (Chogm), but his visit to the Rwandan capital Kigali has been overshadowed by a row over reported comments he made criticising the Government’s scheme to send asylum seekers to the east African nation.

Mr Johnson had suggested he would tell Charles to be open-minded about his Rwanda asylum policy when the two men meet later, but he has stepped back from these comments saying he would not discuss conversations with the Queen or the heir to the throne.

The prince told the world leaders the family of nations was “uniquely positioned to achieve such positive change in our world”, adding: “To achieve this potential for good, however, and to unlock the power of our common future, we must also acknowledge the wrongs which have shaped our past.

“Many of those wrongs belong to an earlier age with different – and, in some ways lesser – values. By working together, we are building a new and enduring friendship.”

Charles, who will succeed the Queen as head of the Commonwealth, went on to say: “For while we strive together for peace, prosperity and democracy, I want 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.

“If we are to forge a common future that benefits all our citizens, we too must find new ways to acknowledge our past. Quite simply, this is a conversation whose time has come.”