The Princess of Wales is set to make her first public appearance of the year at today's Trooping the Colour ceremony for the King's birthday.

Kate, who has been receiving treatment for an undisclosed form of cancer since late February, will ride in a carriage alongside her three children, Prince George, Princess Charlotte and Prince Louis, for the traditional procession through London today.

Her brave decision comes after she retreated from the public eye, missing the Colonel's Review - the traditional rehearsal for Trooping the Colour - on June 8.

Later, she is expected to gather with King Charles and Queen Camilla, her husband Prince William and other royals on Buckingham Palace's balcony for the RAF flypast. 

Another departure from tradition this year is that King Charles III will appear in a carriage, on doctor's orders, rather than on horseback.

So, amid the King's push for a 'slimmed down monarchy', who will be on the Buckingham Palace balcony for Trooping the Colour on June 15?

Which royals were on the balcony last year? 

Naturally, King Charles joined by Queen Camilla on the Buckingham Palace balcony for his first time as King for Trooping the Colour.

They were joined to their right by Charles' eldest son, Prince William, who rode on horseback in the procession before joining his family on the balcony, his wife, Kate, and their three children - Prince George, Princess Charlotte and Prince Louis.

Flanking the King and Queen on the other side were Charles' brother Prince Edward and Sophie, Duchess of Edinburgh.

Princess Anne and her husband Vice Admiral Sir Timothy Laurence were stood just next to Prince William and his family, while the Duke of Kent and the Duke and Duchess of Gloucester stood further away on the other side.

In total, this made 2023 one of the smallest balcony collectives for Trooping the Colour in recent history.

Notable omissions included Prince Andrew, as he had already taken a step back from senior royal duties, and Prince Harry and Meghan Markle.

Who will be on the balcony for the 2024 Trooping the Colour?

The late Queen Elizabeth II would invite her extended family to the palace balcony in her time as monarch, but as reports swirled that Charles was hoping to operate a 'slimmed down' monarchy, only working royals appeared last year.

However, this policy was actually first brought in by the late Queen Elizabeth for her final Trooping the Colour in 2022 - though there were more working royals then than there were a year later.

If it remains in place this year, with Kate's confirmed attendance there is set to be no  change from 2023.

However, her health problems as well as the King's have seen a number of less senior royals emerge to plug the gaps left in their absence.

This was made even more pertinent by the absence of 'spare' Prince Harry and his family, who stood back from their royal duties in 2020. They have reportedly not been invited to the King's birthday celebration for the second year in a row.

So, with he and both his sons' families out of action for a chunk of the last year, King Charles' more distant relatives came in to pick up the slack.

Princess Beatrice, Princess Eugenie, Zara and Mike Tindall and Peter Tindall have all been significant figures at recent royal events - including a Buckingham Palace garden party in May.

The Telegraph have reported that the King has a decision to make over whether or not to bring such figures back in to the balcony fold.