Kate returns to public events at Trooping the Colour

Catherine, Princess of Wales has made her much-anticipated first public appearance of the year at the annual Trooping the Colour parade.

The princess, who is undergoing treatment for cancer, could be seen smiling and waving from the Buckingham Palace balcony at the end of a ceremony filled with pomp and pageantry.

King Charles III, who is also receiving treatment for cancer, travelled in a carriage rather than on horseback.

Thousands waited in the heavy rain for one of the biggest events in the royal calendar.

There were cheers from the crowd as they caught their first glimpse of Catherine and the King heading from Buckingham Palace to Horse Guards Parade.

The carriage procession was met by a sea of mobile phones, with people trying to catch a photograph of the royals through the windows.

The princess was pictured smiling, sitting alongside her children Prince George, Prince Louis and Princess Charlotte - with six-year-old Louis giving a wave to the crowd.

The ceremonial event marks the monarch's official birthday and has been held for over 260 years.

Catherine was all smiles on her way to Horse Guards Parade

The Royal Family looked on from the Buckingham Palace balcony at the RAF flypast

It was Catherine's first public appearance since Christmas and in March she had revealed she was undergoing chemotherapy treatment.

In a statement released on Friday, the princess said she was "not out of the woods yet", and had "good days and bad days", but was "looking forward to attending the King’s birthday parade this weekend with my family".

In a change from last year, she watched the ceremony from a balcony with her children, instead of joining other senior royals on a platform.

Louis danced to a march by the Scots Guards, and was spotted yawning while watching the parade.

His sister, Charlotte, was seen wiping steam off their carriage's windows, as they made their way back to Buckingham Palace.

The three children - George, Charlotte and Louis - stayed with their mother throughout the ceremony

Charlotte could be seen wiping steam off the carriage windows on the way back to the palace

The King, who also continues to have cancer treatment, travelled with Queen Camilla by carriage.

Since the general election was called last month, the palace has had to postpone some events which might have been seen as a "distraction", but the annual Trooping the Colour ceremony went ahead.

As the King's carriage emerged from the Buckingham Palace gates, there were cheers from the crowd.

Prince William, Princess Anne and Prince Edward rode on horseback in military uniform.

The King saluted as he and the Queen arrived at Horse Guards Parade

Prince William, Prince Edward and Princess Anne played a part in the ceremony

Taking the lead in this year's ceremony, as the sovereign's escort, were the Irish Guards, of whom the Princess of Wales is Regimental Colonel. The lead role is rotated between five different regiments of Foot Guards.

During the parade, their flag was "trooped" through the ranks of soldiers.

Made up of troops from the UK, Ireland and the Commonwealth, it was described as "unique" by Sgt Michael Flood, one of the regiment's soldiers.

Meanwhile his colleague Gdsm Colati Kitione, who is from Fiji, said it was an "honour and a privilege" to be asked to take part.

The regiment's mascot - an Irish wolfhound named Seamus - also made an appearance during the parade.

As a serving Guardsman, he parades alongside a drummer, and was inspected alongside the other soldiers, before taking his place at the front of the regiment.

Back on parade today were three of the five horses of the household cavalry that bolted and ran through the streets of London in April.

One, Tennyson, featured in the Sovereign's Escort, while two others - Trojan and Vanquish - were part of the ceremonial guard for the official entrance to the palaces.

Seamus, an Irish wolfhound, is the Irish Guards' mascot

A 41-gun salute rang out from nearby Green Park, followed by an RAF flypast over Buckingham Palace.

Earlier in the day, the man in charge of the flypast, Air Vice-Marshall Mark Flewin, said he was "very confident" it would go ahead, despite the bad weather.

In the end, the skies cleared and the rain stopped just before the flypast.

The Royal Family - including the King, Queen, William and Catherine - came out onto the balcony at the palace to take in the view.

The flypast finished with the Red Arrows acrobatic team flying overhead - leaving trails of red, white and blue in their wake.

Crowds had sheltered under umbrellas in the heavy rain

But the skies cleared just before an RAF flypast

It was a grey and rain-soaked day in central London for much of this year's Trooping the Colour - with heavy showers drenching the troops and the crowds.

But that didn't stop people coming to see the display of pomp and pageantry first-hand - with crowds sheltering under umbrellas as they lined the Mall.

Among those watching in the stands was Prime Minister Rishi Sunak, who was spotted taking a photograph of the parade on his phone.

The parade carried on along the Mall despite the bad weather

Carol and Brian Haddow from Scotland caught a glimpse of Catherine and the Royal Family on the Mall. Mrs Haddow said like “anybody going through chemotherapy, it's a big thing for her to come out and do this”, adding that the princess seemed “fine, happy to be involved”.

One of the soldiers who helped plan Saturday's event praised Catherine, saying that it was “incredibly special” for the princess to attend.

Garrison Sergeant Major Stokes told the PA news agency: “It is probably the only day we see the entire Royal Family together in public and I think the Royal Family really appreciate the day as well”.

There were anti-monarchy protesters at the Trooping the Colour event

Anti-monarchy protesters from the group Republic were among those watching on, waving big yellow flags with slogans including "Not My King".

They were a visible presence gathered on the Mall, not far from Buckingham Palace.

They had not been allowed to use amplified sound, but their loud protest chants could be heard as the royal carriages went past.