Kate, 42, wearing a pale outfit, was pictured arriving at Buckingham Palace in a car sat alongside her children and her husband the Prince of Wales ahead of the event.

The princess, who has been receiving treatment for an undisclosed form of cancer since late February, and her three children Prince George, Princess Charlotte, and Prince Louis were cheered by crowds in The Mall as they left the palace in a carriage for the ceremony.

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The future queen looked relaxed as she travelled along one of London's most famous thoroughfares with her family in a carriage.

She could be seen smiling and talking to her children in the carriage before they arrived at Horse Guards Parade in Whitehall.

William rode on horseback for the procession, alongside the Princess Royal, and the Duke of Edinburgh.

The King, who is also undergoing cancer treatment, rode in a carriage with the Queen, a departure from last year because of his illness, and inspected the officers and guardsmen from the coach rather than from a horse.

When the royal carriages finally came to a stop, Louis was the first to leave, followed by his elder brother George, and sister Charlotte.

Finally, Kate stepped down wearing a Jenny Packham dress, hat by Philip Treacy, and the Irish Guards Regimental Brooch, as she is the regiment's colonel.

In another change from last year, Kate did not join senior family members on a dais, but watched the military spectacle - also known as the Birthday Parade - from a balcony in the Duke of Wellington's former office with her children.

Ahead of the event, she said: "I'm looking forward to attending the King's Birthday Parade this weekend with my family and hope to join a few public engagements over the summer, but equally knowing I am not out of the woods yet.

"I am learning how to be patient, especially with uncertainty.

"Taking each day as it comes, listening to my body, and allowing myself to take this much needed time to heal."

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Princess of Wales's statement in full
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Her appearance was in doubt after she missed the final Trooping rehearsal last weekend.

This is Kate's first official outing of 2024 after she missed engagements at the start of the year when she was admitted to hospital for abdominal treatment.

At the time her condition was thought to be non-cancerous, but tests after the successful operation found the disease, and Kate disclosed the diagnosis in March.

A time frame has not yet been set for Kate's return to a full schedule of public engagements.