It's a match made in society heaven as Hollywood and royalty came together for Ladies Day at Royal Ascot today. Stanley Tucci, 65, who is a regular at royal events and dinner parties, looked just as comfortable in a landau as he travelled to the Berkshire racecourse alongside his wife, Felicity Blunt. The American actor dressed for the part as he opted for a black top hat with an impeccably tailored suit. Meanwhile, the sister of Tucci's The Devil Wears Prada co-star, Oscar nominee Emily Blunt, put on a stylish display in a floral dress for the most popular day of the festival, when racegoers pull out all the fashion stops. Another famous face making their debut in the royal family's Ascot procession is the Earl Snowdon's long-term girlfriend, Isabelle de La Bruyere, as the pair had the honour of riding alongside King Charles and Queen Camilla. Smiling at the crowds, Princess Margaret's son David Armstrong-Jones, 64, has been dating the French art dealer since 2022, two years after he split from his wife Serena Stanhope after 27 years of marriage. While the loved-up royal couple attended Ascot together last year, today is the first time Isabella has joined the royal carriage procession - as she cut a striking figure in a white dress with a black belt. Stanley Tucci, 65, who is a regular at royal events and dinner parties, looked just as comfortable in a landau as he travelled to the Berkshire race course for day three of Ascot today Stanley looked dapper in his top hat and sunglasses as he joined the royal carriage procession Travelling behind King Charles and Queen Camilla in the second open-top landau were the Princess Royal, her husband, Vice Admiral Sir Timothy Laurence, as well as the Duke and Duchess of Edinburgh. Princess Anne's daughter, Zara Tindall, 45, was pictured in the third carriage, riding alongside Princess Zahra Aga Khan, daughter of the Aga Khan, Qatari businessman Sheikh Hamad bin Abdullah Al Thani, and legendary Irish racehorse trainer Willie Mullins. Senior royals joined thousands of stylish racegoers who put their best fashion foot forward as Ladies Day gets underway. However, the warm weather meant sleeveless dresses and airy skirts were popular sartorial choices - as the UK braces for the start of a six-day heatwave with temperatures expected to rise to 27C this afternoon. A static area of high pressure building across mainland Europe – known as a 'heat dome' – is resulting in increasingly warm and humid air for southern England.London, the East, South East and South West regions were placed under the amber alert, while the Midlands faces a yellow warning. There are no alerts for the North.These warnings run from midday today until next Tuesday at 8pm – although the Met Office forecast currently suggests the heatwave could last until at least Wednesday.The amber alert states that the areas covered are likely to see 'a rise in deaths, particularly among those aged 65 and over or with health conditions', while 'significant impacts are likely across health and social care services' due to the heat. Carole Middleton returns to Royal Ascot for Ladies Day Stanley's wife, Felicity Blunt was all smiles as she was driven to the racecourse in a royal landau The Devil wears a top hat! Stanley waving at the crowds as he arrived for Royal Ascot The King tipping his hat as he arrived at the Berkshire racecourse with Queen Camilla From left to right: Prince Edward, the 2nd Earl of Snowdon, Isabelle de La Bruyere, and Zara Tindall Princess Anne's daughter Zara turned heads in a textured butter yellow midi dress King Charles led a contingent of senior royal as Ladies Day got underway at Ascot Another famous face making their debut in the royal family's Ascot procession is the Earl Snowdon's long-term girlfriend, Isabelle de La Bruyere (not pictured), as the pair arrived alongside King Charles and Queen CamillaRoyal Ascot, the jewel in the crown of the UK racing calendar, started on Tuesday with the Queen Anne Stakes and will run until Saturday.Joining the King and Queen in the Royal Enclosure today were Princess Anne, 75, Sophie, Prince Edward, as well as the 2nd Earl of Snowdon, David Armstrong-Jones, who is 25th in line to the throne. The King's cousin - who owns a bespoke furniture-making business - was accompanied by his long-term girlfriend, art expert Isabelle, less than two weeks after she joined the Royal Family for Peter Phillips and Harriet Sperling's wedding. Also in attendance today was Princess Zahra, the daughter of the owner of the stolen racehorse Shergar, who recently spoke about the Derby-winning legend's kidnapping in 1983.Daughter of the Aga Khan, revealed the colt was killed 'in an awful way' and a ransom was never paid to stop the money getting into the wrong hands.It is 45 years since the big bay with a white blaze won the Derby at Epsom by 10 lengths, a margin which to this day stands as a record for a race first run in 1780.On the night of February 8, 1983, intruders broke into the Aga Khan's Ballymany Stud in County Kildare and kidnapped the horse.At the time, the IRA were the main suspect behind the kidnapping, which involved six armed men.It has been generally accepted that his abductors were ill-equipped to control a thoroughbred stallion, and he was killed shortly afterwards.Royal Ascot, the jewel in the crown of the UK racing calendar, started on Tuesday with the Queen Anne Stakes and will run until Saturday.Radiant guests turned the racecourse into a sea of colourful ensembles as they stepped out for the prestigious occasion.Those trying to command attention amongst the crowd of thousands opted for unique garments - including a Spanish-inspired bright red dress - but her extra-large feather hat stole the show.The wacky, gravity-defying style of hats is permitted in most areas at Ascot, except in the Royal Enclosure.'A hat or headpiece with a solid base of four inches in diameter is mandatory in the Royal Enclosure,' explained the Royal Ascot website.'Fascinators are not permitted. Novelty hats (i.e. ones which are excessively oversized, or are promoting or marketing any product or brand) are not permitted.'Some of the celeb attendees will join society names in the Royal Enclosure - the most exclusive area of the racecourse, which has its own strict dress code.While no dress code rules apply in the Windsor Enclosure, although the majority of guests choose to dress up regardless, a strict dress code operates across the Royal and Queen Anne Enclosures.Ladies must wear 'a dress or skirt falling just above the knee or longer' and 'shoulder straps that are a minimum width of 1 inch / 2.5cm,' along with 'a hat or headpiece with a solid base of four inches in diameter.''Fascinators are not permitted. Novelty hats (i.e. ones which are excessively oversized, or are promoting or marketing any product or brand) are not permitted.'Strapless, off-the-shoulder and one-shoulder items are also banned in the Royal and Queen Anne Enclosures.Shorts of any kind are not permitted. But having been included in the dress code since 1971, trouser suits remain a popular choice - although they mustn't be mismatched. The event's official lookbook this year was curated by menswear specialist Daniel Fletcher, who has previously designed for the likes of Louis Vuitton, JW Anderson and Victoria Beckham.