The King was joined by his maternal cousins, Lady Sarah Chatto and the 2nd Earl of Snowdon, at Ladies Day on day three of Royal Ascot.
Charles returned to the Berkshire racecourse on Thursday after missing day two of the meet as he conducted audiences at Buckingham Palace.
The King has long shared a close bond with Princess Margaret and Antony Armstrong-Jones's children, Sarah and David. Watch their arrival below...
Sarah was joined by her husband and British artist, Daniel Chatto. The pair have two sons – Samuel, who shares his parents' artistic talents, and Arthur, who is in the Royal Marines.
Meanwhile, the Earl of Snowdon shares daughter Lady Margarita and son Charles with his ex-wife, Serena.
Charles and Camilla were also joined at the races by the Duke and Duchess of Edinburgh, the Princess Royal and Vice Admiral Tim Laurence, and Mike and Zara Tindall.
See the best photos from Ladies Day…
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© GettyThe King and Queen on Ladies Day
The King looked smart in a grey morning suit with a blue waistcoat on Ladies Day while the Queen chose a white pleated dress with a large emerald brooch.
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© GettyRoyal cousins
Lady Sarah Chatto and Daniel Chatto shared a carriage with the Princess Royal and Vice Admiral Sir Tim Laurence.
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© GettyBeautiful in blue
For her third appearance at Royal Ascot, Princess Anne opted for a light blue embroidered ensemble with a wide-brimmed floral hat.
Her cousin, Lady Sarah Chatto, looked elegant in a cobalt blue dress with an oversized hat.
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© GettyThe Duchess of Edinburgh
The Duchess of Edinburgh is a fan of the shirt dress and she didn't disappoint for her second appearance at Royal Ascot.
Prince Edward and Sophie celebrated their Silver Wedding anniversary at the races on Wednesday, with the Duchess opting for a bridal-esque dress with floral applique by Suzannah London.
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© GettyZara Tindall
Mike and Zara Tindall made their third appearance at Royal Ascot on Ladies Day.
Zara looked beautiful in a puff-sleeved frock by Rebecca Vallance with a boater-style hat by Sarah Cant.
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© James Veysey/ShutterstockZara Tindall's outfit
A full-length look at Zara's outfit. The powder blue dress included a belt which cinched her in at the waist.
The equestrian teamed her dress with metallic shoes from Dune and a Tusting clutch bag.
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© GettySophie's outfit
A full-length look at Sophie's Ladies Day look, which she teamed with a bold red clutch bag.
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© GettyAll in the details
Zara sported pearl drop earrings from Laurence Costa and kept her cool in MONC's Belleville sunglasses.
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© James WhatlingSweet moment
King Charles was captured greeting his stepson, Tom Parker Bowles, with a kiss on both cheeks as he arrived in the royal box.
Camilla shares son Tom and daughter Laura Lopes with her ex-husband, Andrew Parker Bowles.
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© GettyAnd they're off!
Things got very tense as the King and Queen cheered on one of their horses Gilded Water in the King George V Stakes.
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© James WhatlingA tense moment
The Queen was very animated during the nail-biting race, but sadly no victory for Their Majesties on this occasion.
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© GettyRoyal sisters-in-law
A glamorous Camilla and Sophie chatted and giggled together in the royal box.
The Queen stunned in a white silk crepe dress by Dior and a matching hat by Philip Treacy.
She accessorised with the late Queen Elizabeth II's jade and diamond brooch
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© GettyA right royal laugh
We'd love to know what Edward and Sophie were laughing about with Champion Jockey Frankie Dettori.
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© GettyStylish couple
Zara often tops the best dressed lists and she has not disappointed with her race day attire this week.
The Tindalls will celebrate their 13th wedding anniversary next month.
