The Princess of Wales has dazzled in green after shunning military uniform for the first Trooping the Colour of King Charles' reign.
Kate, 41, was joined by Queen Camilla, 75, as well as Prince George, nine, Princess Charlotte, eight, and Prince Louis, five, in a carriage procession as they made their way from Buckingham Palace to Horse Guards Parade to watch the first birthday parade for the King.
Not only is the parade a first for Charles as King, it is also the first for Kate in her role as colonel of the Irish Guards, which she took over from her husband Prince William last year.
This meant she could have worn military dress for the event and even ridden a horse - but instead, she opted for a green ensemble with a huge hat and to travel in a carriage.
However, she did pay tribute to her regiment by wearing green, the colour of the Irish Guards, and a stunning regimental brooch.
Her gorgeous green dress was designed by Andrew Gn, and featured bejewelled a design, while her matching, wide-brimmed green hat was designed by Philip Treacy.
Kate also chose to wear the late Princess Diana's earrings, which feature two blue sapphires, each encircled with a diamond halo.
She appeared alongside Queen Camilla, who wore a red silk dress, reflecting the "heritage of the Grenadier guards" because of her new role of colonel of the Grenadier guards, explained BBC Presenter Huw Edwards.
The dress, by London fashion designer Fiona Clare, is inspired by the uniform of the Grenadier guards, complete with a "rank insignia of a fill colonel on the epaulettes of the dress".
Brothers Prince George and Prince Louis looked dapper in matching navy suits and red ties, while their sister Charlotte wore a beautiful red and white dress, as they eagerly waved to the public along the Mall.
Also travelling in carriages were the Duchess of Edinburgh and Princess Anne's husband Timothy Laurence as well as the Duke and Duchess of Gloucester.
It was last year that she became the Colonel of the Irish Guards - a position previously held by her husband Prince William.
And already this year, she has fulfilled colonel duties, which have included taking part in the Irish Guards' well-known St Patrick's Day parade.
However, William did ride on horseback alongside his father Charles - who is the first monarch in 37 years to do so.
The colour, or regimental flag, trooped in front of hundreds of Guardsmen and officers is the King's Colour of the 1st Battalion Welsh Guards.
During the Trooping ceremony, the 74-year-old King will inspect the Guardsmen, in their scarlet tunics and bearskins, standing in two rows on Horse Guards before the colour is trooped.
After the parade, the King, accompanied by Kate, Camilla and other family members, will return to Buckingham Palace for RAF the fly-past, which will conclude the day's celebrations.
An extended military flypast will take place after the display on Coronation day last month had to be scaled down due to bad weather.
The Ministry of Defence (MoD) said the aircraft will take off from 15 locations up and down the UK before meeting in the southeast of England and flying across London.
The event will feature a mix of aircraft, ranging from the Battle of Britain Memorial Flight dating back to the 1940s and the C-130 Hercules on its final ceremonial flight to multiple Typhoon fighter jets and the Envoy IV CC1, which is making its flypast debut.
At the front of the flypast will be a Juno HT1 piloted by Flight Lieutenant Tom Knapp from 60 Squadron, No 1 Flying Training School based at RAF Shawbury.
The event will end in a show of red, white and blue from the pilots of the Red Arrows.
