Trooping the Colour is a huge occasion on the royal calendar each year and a highlight for HELLO! - with the King and his family out in force on the Buckingham Palace balcony, mischievous royal children and some of the best fashion on display.
It's a public celebration which marks the monarch's official birthday, with 2024 marking Charles' second Trooping the Colour of his reign on Saturday 15 June.
For his first birthday parade in 2023, the King rode in the procession on horseback – marking the first time the sovereign has done so since the late Queen Elizabeth II in 1986.
However, amid Charles' ongoing cancer treatment, Buckingham Palace has revealed that the King will participate in the ceremony via carriage with the Queen.
After the ceremony, the royals gather on the Buckingham Palace balcony to watch a spectacular flypast from the Royal Air Force.
While extended members of the royal family would regularly appear on the balcony during the late Queen's reign, Charles has only invited senior working royals, such as the Prince and Princess of Wales, the Duke and Duchess of Edinburgh and the Princess Royal.
It remains to be seen whether the Princess of Wales and her three children, Prince George, Princess Charlotte and Prince Louis, will participate in this year's event, amid Kate's own ongoing cancer treatment.
First things first though, why does the King celebrate his birthday twice?
Trooping the Colour: history and name explained
His Majesty celebrates two birthdays: his actual birthday on 14 November and his official birthday on the second Saturday of June at Trooping the Colour – but why?
Historically, official celebrations to mark a sovereign's birthday have often been held on a day other than their birthday. This is usually true when their actual birthday does not land in the summer months. The reason, in typical British fashion, comes down to the weather.
The tradition started in 1748 with George II, who was born in chilly November. Instead of risking his subjects catching a cold, he combined his birthday celebration with the annual spring parade known as Trooping the Colour.
Why is it called Trooping the Colour?
'Colours' refers to the flags that represent the different regiments in the British Army. The army used these flags so that soldiers could spot their unit on the battlefield. 'Trooping', meanwhile, refers to the marching up and down of the troops.
Trooping the Colour therefore refers to when the flags of the different regiments are displayed. Each year, a different regiment is chosen to 'troop' their 'colour' and 2022's event saw the colour trooped by the 1st Battalion, Irish Guards.
What is Trooping the Colour?
Over 1,400 parading soldiers, 200 horses and 400 musicians come together each June in a great display of military precision, horsemanship and fanfare to mark the King's official birthday.
The streets are lined with crowds waving flags as the parade moves from Buckingham Palace and down The Mall to Horse Guard's Parade, alongside members of the royal family on horseback and in carriages.
Royal photographer Tim Rooke, who has been capturing the royals for over 25 years, previously told HELLO! in 2021 that he captured some of the "nicest family photos" at the 2019 ceremony, where Prince Louis made his adorable debut.
He's even managed to capture some incredible off-duty photos of Prince George, Princess Charlotte and Louis with their royal nanny before the late Queen and her family assembled on the balcony at Buckingham Palace.
He said: "Some of the kids were in the window of Buckingham Palace waiting with their nanny, watching as the [then] Duke and Duchess of Cambridge came back, so that made some quite fun pictures, and then once they're back, then they all come out on the balcony, so it made some very nice family pictures."
What is the history behind Trooping the Colour?
According to the Household Division, the British Army's regimental flags were historically described as 'colours' because they display the uniform and insignia of the soldiers from different military units
The army used these flags so that soldiers could easily spot their unit when they were on the battlefield because it used to be quite easy to get lost in battle.
Officers would regularly march up and down in front of soldiers, known as 'trooping,' with their flags on displays, known as 'colours' so that everyone would know which ones would belong to which regiment.
The royals have mostly stuck to tradition when it comes to the format of the ceremony.
Tim said: "What used to happen was the Queen [Elizabeth II] would go down to Horseguards Parade and then the other members of the royal family would come back and go into the palace and the Queen would stand outside the gates of the palace and review the soldiers as they marched past, and the Duke of Edinburgh would stand next to her."
While the press pack of photographers take up their official position on the Queen Victoria Memorial in front of Buckingham Palace, Tim revealed there's also another key spot to capture the royals.
He told HELLO!: "One of the nicest pictures that you can get is if you stand on The Mall outside Clarence House because all the staff come out and wait outside. When the carriages come from the palace, there's interaction between the members of the royal family between staff and friends, who stand outside Clarence House, so actually that makes a better picture than the official position."
Who attends Trooping the Colour?
Members of His Majesty's family usually attend, including his siblings, Princess Anne and Prince Edward, and their respective spouses, as well as the late Queen Elizabeth's II's cousins, the Duke and Duchess of Gloucester, the Duke of Kent and Princess Alexandra.
In recent years, we've seen Prince George, Princess Charlotte and Prince Louis, make their debuts at the event, alongside their cousins, Savannah and Isla Phillips.
George and Savannah had one of the most memorable moments at Trooping the Colour in 2018 when Savannah put her hand over her cousin's mouth to stop him singing.
With the eyes of the world upon them, the royal children have proved they're just like any other kids with their cheeky antics and their awe-struck expressions during the fly-past.
The Wales children also made their debut in the carriage procession at Trooping the Colour 2022 and joined mum Kate and Queen Camilla in the procession last year.
What do the royals wear to Trooping the Colour?
Fashion is always a talking point of any major royal event and the Princess of Wales often turns to her go-to designer, Alexander McQueen, for her outfits, beginning with a cream ruffled ensemble for her debut at the event in 2011.
Before stepping back as a senior royal, the Duchess of Sussex appeared at the ceremony twice, opting for a stunning blush pink off-the-shoulder dress from Carolina Herrera in 2018 and a navy and white number, designed by her wedding dress designer, Clare Waight Keller of Givenchy in 2019.
The royal children's outfits also get plenty of attention, with Kate and the Duchess of Edinburgh turning to traditional labels such as British brand, Rachel Riley, for outfits for their little ones.
Lady Louise Windsor has been seen in several of Rachel Riley's classic pieces at Trooping the Colour over the years, including a mauve and yellow printed dress with a Peter Pan collar under a matching scalloped cardigan in 2012.
"It makes me feel really proud, I'm a small business owner and it makes me feel part of British history," Rachel previously told HELLO! in 2021.
"On those formal occasions like when the royal family are on the balcony of Buckingham Palace, I think it's important to make sure their children are wearing timeless and classic designs that really won't show their age in future and in photographs that won't represent a specific time."
Throughout the decades, the royals have been known to borrow their siblings' clothes or pass down outfits from generation to generation; in the case of Louis, he wore a blue and white two-piece that once belonged to his father, William, and uncle, Prince Harry, at his Trooping the Colour debut.
When was the first Trooping the Colour?
The first Trooping the Colour ceremony is believed to have originated during the reign of King Charles II from 1660 to 1685. However, it wasn't until 1748 that it was decided that this parade would be used to mark the official birthday of the sovereign and it became an annual event after George III became King in 1760.