King Charles led the procession on horseback in his first-ever birthday parade as monarch.
The military extravaganza featured the most distinguished regiments in the British Army honoring their Colonel in Chief by parading to honor his anniversary.
It is the first time a monarch has ridden at Trooping the Color in more than 30 years.
The King withstood the scorching heat while riding his horse alongside son Prince William, sister Princess Anne, and brother Prince Edward, who is riding in the parade for the first time today.
Other members of the Royal Family, including Queen Camilla and the Princess of Wales, as well as Prince George, Princess Charlotte, and Prince Louis, followed in carriages.
According to the BBC’s Huw Edwards, the King’s horse was seen acting “lively” and “excited” as he rode it down the Mall.
When the procession arrived at Horse Guards Parade, Charles took the salute as Colonel in Chief of the Household Division’s seven regiments.
This year, the Welsh Guards will march their colors during the ceremony.
It is the reigning monarch’s first appearance at Trooping the Color since 1986 when Queen Elizabeth II last rode.
The Queen’s favorite steed for Trooping and formal events were Burmese.
The horse was a gift from the Royal Canadian Mounted Police and was utilized for 18 years, from 1969 to 1986, before being retired to Windsor.
The Queen then decided that rather than training another charger for the occasion, she would be driven in a carriage in the future.
For the first time since 1989, the five Foot Guards regiments – the Welsh, Scots, Irish, Coldstream, and Grenadier – marched together at Trooping.
Charles rode onto Horse Guards Parade in Whitehall as the nation’s head of state, having deputized for Queen Elizabeth II at last year’s ceremony, also known as the Birthday Parade.
Following the parade, the King will return to Buckingham Palace, followed by Camilla and other family members, for the RAF fly-past, which will conclude the day’s celebrations.