The King has an established pattern of marking his birthday through public duties

Princess Kate and Prince William have marked King Charles’s 77th birthday with a public message on social media, sharing warm wishes alongside a new photograph of the monarch.

The post, issued this morning from their official account, read: “Happy Birthday to His Majesty The King!” and was paired with a recently captured image of Charles walking through the gardens at Highgrove House in Gloucestershire.

The Prince and Princess of Wales rarely post personal messages outside major family milestones, making today’s greeting a notable moment of visibility as the King continues a full programme of engagements.

The Royal Family’s official Instagram account also recognised the occasion, thanking the public for their support.

“77 today! Thank you for the kind words and well wishes on His Majesty’s Birthday,” the message read, as senior royals and well-wishers joined in sending greetings.

Charles and Queen Camilla are spending the day in South Wales, where they have travelled to Cyfarthfa Castle in Merthyr Tydfil.

The visit is centred on the region’s artistic and cultural heritage, with the couple meeting community members involved in local arts initiatives.

It continues the King’s established pattern of marking his birthday through public duties rather than private celebrations, reflecting his long-standing commitment to cultural institutions across the UK.

Prince William and Princess Kate send public message to King Charles as he leaves England with Camilla | GETTY

This year’s birthday arrives during a period of considerable change within the royal household.

In recent weeks, the King has taken the unprecedented step of formally removing his brother Andrew Mountbatten-Windsor’s princely status and HRH designation.

The move became official on November 3 with the publication of Letters Patent in The Gazette, declaring that Andrew would “no longer be entitled to hold and enjoy the style, title or attribute of ‘Royal Highness’ and the titular dignity of ‘Prince.'”

The decision followed months of internal discussions and the support of senior royals, including the Prince of Wales.

Former royal press secretary Ailsa Anderson stated that although Andrew had previously offered to relinquish his royal titles, he had been delaying the process, prompting the monarch to act decisively.

She said he had been “dragging his heels” and that Charles ultimately concluded “enough is enough.”

Ms Anderson acknowledged the weight of the decision for the King, telling People Magazine: “It must be mixed emotions for him.”

King Charles and Queen Camilla viewing the birthday cake in Wales| PA

She added that the complex blend of familial bonds and constitutional responsibilities contributed to the length of time it took to conclude.

“It is family and monarchy, and when the lines are blurred, it’s very difficult for them. I’m just glad the late Queen is not around to see this.”

The birthday message from Princess Kate and Prince William comes against this backdrop, offering a moment of unity and public support as the monarch continues to balance personal challenges with a demanding schedule of national and Commonwealth duties.