The Queen has appealed to Commonwealth leaders to appoint her son, Prince Charles, to succeed her as their head.
She said it was her “sincere wish” that Prince Charles takes over “one day”, as she opened the Commonwealth Heads of Government Meeting (CHOGM) in London.
The role is not hereditary and will not pass automatically to the Prince of Wales on the Queen’s death.
The 53 leaders, gathered at Buckingham Palace, are to make a decision on the succession on Friday, No 10 has said.
Addressing the gathering of dignitaries, royals and the prime minister, the Queen said it was a “pleasure, this time, to welcome you to my home” for the biennial meeting.
She said it remained a “great pleasure and honour to serve you” and to observe “with pride and satisfaction that this is a flourishing network”.
She added: “It is my sincere wish that the Commonwealth will continue to offer stability and continuity for future generations, and will decide that one day the Prince of Wales should carry on the important work started by my father in 1949.”
Issues under discussion at the two-day summit also include ocean conservation, cyber security, and trade between the countries.
Singer Emeli Sande began proceedings with a rendition of the National Anthem in the palace’s ballroom.
Prime Minister Theresa May told the leaders the summit would “take on some of the 21st Century’s biggest questions”.
Speaking in the ballroom, which was decorated with flags of the 53 nations, Mrs May said: “There have been difficulties, successes, controversies, but I believe wholeheartedly in the good that the Commonwealth can do.”
The prime minister also thanked the Queen for hosting the event, calling the monarch a “steadfast and fervent champion” of the Commonwealth.
Outside, more than 100 officers and soldiers from the Coldstream Guards were in honour guard, wearing scarlet tunics and bearskins, as a 53 gun salute marked the formal opening.