King Charles will attend Trooping the Colour on June 15, Buckingham Palace has confirmed, while Kate Middleton will miss the occasion as she continues cancer treatment. As exclusively reported by Vanity Fair, Charles was determined to attend the 260-year-old ceremony, which marks the monarch’s official birthday and his medical team has given him the green light to attend the national occasion.

King Charles had hoped to ride at the ceremony on horseback, as he did last year for his first Trooping ceremony as sovereign, but palace aides said on Thursday that Charles will ride in a State Landau carriage.

Princess Kate will not attend the historic parade, which is watched by hundreds of thousands of people around the world, as she continues to stay away from the media spotlight. Kate would ordinarily have been required to take the salute in her role as Colonel of the Irish Guards, however, the palace has confirmed this will be carried out by Lieutenant General James Bucknall, the former commander of the Allied Rapid Reaction Corps. It is expected that Prince William will be in attendance, but it is not known if the couple’s children Prince George, Princess Charlotte and Prince Louis will attend.

Thursday’s announcement from Buckingham Palace will be seen as a positive step forward for Charles, who is said to be “doing well” as he undergoes cancer treatment. Earlier this month, the monarch returned to official duties, including a visit to a cancer center in London and attending a Buckingham Palace garden party, although his normally busy schedule has been scaled back on the advice of his medical team.

Last month, sources close to the 75-year-old monarch told VF that he was determined to attend Trooping the Colour, which has been described by aides as “a date-specific landmark of the national ceremonial calendar.” While King Charles will not ride on horseback, he will take part in the ceremony and conduct the review seated in a State Landau, a nod to some of the adjustments being made to his public work. There are a number of engagements Charles is determined to attend including Royal Ascot and the forthcoming D-Day 80th anniversary appearances in Portsmouth and Normandy in June.

There were questions about whether Trooping the Colour would go ahead after Britain’s Prime Minister Rishi Sunak called a General Election earlier this month. The Royal Family suspends all engagements during the run up to an election campaign, but the event was deemed a day of importance and will go ahead, palace aides said Thursday. “It is not something that could or should be postponed in light of the general election,” a source told VF.

Neither the Palace nor the Ministry of Defence has announced which other members of the Royal Family will attend the ceremony, though Charles is said to want all working members of the family in attendance and on the Buckingham Palace balcony for the flypast of military aircraft, the highlight of the day.