The queen will not join other royal family members in the traditional carriage rides to the Horse Guards and will instead appear on the balcony of Buckingham Palace, joined by her cousin, the Duke of Kent, the palace confirmed Wednesday.
In the queen's absence, her son Prince Charles, the heir to the throne, will take the royal salute on the parade ground and inspect the troops on the queen's behalf, joined by his son, Prince William, and his sister, Princess Anne.
Elizabeth will take a salute from the cavalry as they go past Buckingham Palace on their return from the parade.
This is the first time in Elizabeth's 70-year reign that she will take a salute from the balcony at Buckingham Palace, and the first time Prince Charles will stand in for her on the parade ground.
Trooping the Color, also known as the Queen's Birthday Parade, is an annual tradition that has marked the British monarch's official birthday for more than 260 years, according to the Associated Press.
The 96-year-old queen, the first monarch in Britain's history to reach a Platinum Jubilee, has been suffering from mobility issues.
She attended the Chelsea Flower Show last week but was escorted by golf car instead of touring the gardens on foot, as she has done in years past.
Earlier this month, the queen attended the Royal Windsor Horse Show but, again, did limited walking.
Prior to the horse show, Elizabeth's last public appearance was in late March at a service of Thanksgiving for her husband, Prince Philip, who died last year at the age of 99.
While the queen has continued to maintain a busy schedule of virtual meetings, phone calls and private engagements, her public appearances have become increasingly rare.
She did not attend the opening of Parliament in early May, marking the first time in nearly 60 years and only the third time in her 70-year reign that she has not attended.
At the time, Buckingham Palace said the queen "continues to experience episodic mobility problems."
The queen has also battled several health conditions over the past year, including COVID-19 and an overnight hospitalization last October for what Buckingham Palace described at the time as "preliminary investigations."
The queen's Platinum Jubilee is being celebrated in the U.K. through Sunday. In addition to Trooping the Color, celebratory events include a service of thanksgiving at St. Paul's Cathedral, a star-studded concert at Buckingham Palace and a Platinum Jubilee Pageant.
At Trooping the Color, the queen will be joined by members of the royal family, in addition to the over 1,400 soldiers and 200 horses who will participate in the parade.
The royals will watch the parade from the balcony of Buckingham Palace. Joining the queen this year on the balcony will be Prince Charles and Camilla, Duchess of Cornwall; the Duke and Duchess of Cambridge, William and Kate, along their three children; the Earl and Countess of Wessex, Edward and Sophie, along their two children; the Princess Royal and Admiral Sir Timothy Laurence; the Duke and Duchess of Gloucester; the Duke of Kent; and Princess Alexandra.
Other members of the royal family, including Prince Harry and his wife, Meghan, the Duchess of Sussex, will watch the parade from the Major General’s Office, an office in Buckingham Palace that overlooks the parade ground.