Queen Elizabeth II will make two appearances on the Buckingham Palace balcony on Thursday, kicking off four days of public events to mark her historic Platinum Jubilee.
The extent of the 96-year-old monarch's involvement in the celebrations for her record-breaking 70 years on the throne has been a source of speculation for months.
She has cut back drastically on her public appearances since last year because of difficulties standing and walking — and a bout of COVID-19.
But royal officials confirmed that she would take the salute of mounted troops from the balcony after a military parade called Trooping the Colour.
The centuries-old ceremony to officially mark the sovereign's birthday has previously seen the queen take the salute on horseback herself.
Her 73-year-old son and heir, Prince Charles, will step in this year, supported by his sister, Princess Anne, 71, and his eldest son, Prince William, 39.
Joining senior royals watching the display of military precision will be Charles' younger son, Prince Harry, and his wife, Meghan, on a rare visit from California, Buckingham Palace confirmed.
But the queen's disgraced second son, Prince Andrew, 62, is not expected to join them.
She will return to the balcony later to watch a flyby of military aircraft, including iconic models from World War II, the palace said.
At nightfall, the queen will be at Windsor Castle, west of London, to take part in a ceremony to light more than 3,000 beacons across the country and the Commonwealth of 54 nations that she heads.
Parties, parades, concerts
Elizabeth was a 25-year-old princess when she succeeded her father, King George VI in 1952, bringing a rare touch of glamour to a battered nation still enduring food rations after World War II.
Seventy years on, she is now the only monarch most Britons have ever known, becoming an enduring figurehead through often troubled times.
FILE - This photo combo shows Britain's Queen Elizabeth II during the State Opening of Parliament, London, in April, 1966 on the left and Nov. 15, 2006, on the right.
Britain's first and very likely only Platinum Jubilee will see street parties, pop concerts and parades until Sunday in potentially the last major public celebration of the queen's long reign.
It has not yet been confirmed if she will attend a thanksgiving service at St Paul's Cathedral on Friday, while her planned attendance at horse racing showcase The Derby on Saturday is off.
She could yet put in a final appearance — again from the palace balcony — on Sunday, at the climax of a huge public pageant involving 6,000 performers.
In a message, the queen thanked everyone involved in organizing the community events in Britain and around the world.
FILE - Britain's Queen Elizabeth II and Camilla, Duchess of Cornwall, at the G7 summit in Cornwall, England, June 11, 2021.
"I know that many happy memories will be created at these festive occasions," she said.
"I continue to be inspired by the goodwill shown to me, and hope that the coming days will provide an opportunity to reflect on all that has been achieved during the last 70, as we look to the future with confidence and enthusiasm."
Attention turning to succession
The jubilee, held against a backdrop of rising inflation that has left many Britons struggling, is being seen not just as respite for the public after two years scarred by the pandemic but also for the royals.
Harry, 37, and Meghan, 40, caused shockwaves in early 2020 by moving to North America, from where they have publicly criticized royal life.
In April last year, she lost her husband of 73 years, Prince Philip, and was forced to sit alone at his funeral because of coronavirus restrictions.
FILE - Britain's Queen Elizabeth II, then Princess Elizabeth, stands with her husband Prince Philip, the Duke of Edinburgh, and their children Prince Charles and Princess Anne at Clarence House, the royal couple's London residence, August 1951.
Since then, she has struggled with her health and also the fallout from Andrew's links to the convicted sex offenders Jeffrey Epstein and Ghislaine Maxwell.
Andrew, who in February settled a U.S. civil claim for sexual assault, has effectively been fired from his royal duties.
Attention is increasingly turning to the succession, and the monarchy's future at home and in the 14 other Commonwealth countries where the queen is also head of state.
Her approval rating among Britons remains high at 75%, according to a poll by YouGov published Wednesday, but Charles is only at 50%.
A total of 62% still want a monarchy, although younger people are split, with 33% in favor, and 31% wanting a republic.
Only 39% said they thought there would still be a monarch in 100 years' time.