King Charles burst into fits of laughter today as he made a surprise visit to the Royal Windsor Horse Show while his cancer treatment continues.  

The high-spirited monarch looked delighted and was spotted pointing with a smile on his face as he watched the event in Berkshire. 

He was also seen chatting happily to officials at the Royal Windsor Horse Show while sheltering under umbrellas in the pouring rain.

The King was present for the third day of the event which his late mother Queen Elizabeth II also often attended as a spectator. 

King Charles burst into fits of laughter today as he made a surprise visit to the Royal Windsor Horse Show while his cancer treatment continues

The high-spirited monarch looked delighted and was spotted pointing with a smile on his face as he watched the event in Berkshire

He was also seen chatting happily to officials at the Royal Windsor Horse Show while sheltering under umbrellas in the pouring rain

It comes just three days after Charles visited hospital patients in London upon his return to public-facing royal duties.

Other royals also attended the Royal Windsor Horse Show yesterday including Prince Edward and his wife Sophie and Princess Anne and her husband Vice Admiral Sir Timothy Laurence.

The Duchess of Edinburgh looked stylish in a khaki blazer and leather skirt at the show. 

Sophie, 59, completed her ensemble with a white blouse and burgundy leather boots.

The photos of Charles grinning in the stands come after Zara Tindall was seen beaming as she gave her Uncle Charles a big hug today. 

It comes just three days after Charles visited hospital patients in London upon his return to public-facing royal duties

King Charles laughing at the third day of the Royal Windsor Horse Show today

Charles was seen pointing with a smile on his face in the stands 

Charles's appearance and cheerful manner will come as a relief to many and suggest that he is making positive progress after almost three months of cancer care as an outpatient

The pair were spotted in a warm embrace and shared a few words as they met on site. 

Charles's appearance and cheerful manner will come as a relief to many and suggest that he is making positive progress after almost three months of cancer care as an outpatient.

At his visit to University College Hospital Macmillan Cancer Centre on Tuesday, the King spoke of his 'shock' at being diagnosed with cancer as he met fellow patients. 

Charles candidly described the experience of being told he had the disease, as he learned about the latest treatments and chat to staff providing the pioneering care.

He also reassured those who asked about the state of his health, saying: 'I'm well.'

King Charles III and Zara Tindall at day three of the Royal Windsor Horse Show today

Zara Tindall gives her uncle King Charles a hug at the Royal Windsor Horse Show this morning

King Charles III and Zara Tindall at day three of the Royal Windsor Horse Show today

The King, who looked relaxed and in good spirits, was joined on the visit by Camilla, and went on impromptu walkabouts, meeting staff who had stopped to catch a glimpse of the royal couple.

In another engagement on Wednesday, Charles viewed his Coronation Roll at Buckingham Palace in what was his second public-facing event since his diagnosis. 

He told those who created the historic document that 'you deserve a very stiff drink'. Charles viewed the roll with Camilla, and marvelled at the handwritten and lavishly decorated artefact.