The Princess of Wales looked typically stunning as she took part in the King's official birthday parade in London today. Kate, 44, opted for a light blue and white ensemble, teamed with a matching hat as she joined her children Prince George, 12, Princess Charlotte, 11, and Prince Louis, 8, for the annual Trooping the Colour.Photographed arriving for the celebrations alongside a dapper Prince William, who was dressed in his military uniform, the princess completed her glamorous look with a pair of glitzy pearl floral earrings. The Royal Family joined thousands of spectators in Whitehall for the annual event that brought together some of the military's most prestigious regiments to mark Charles' anniversary.The occasion was once an affair that saw the balcony at Buckingham Palace brimming with at least 44 royals as it included more distant relatives. But over the last few years, only working royals - and the Waleses' children - have attended the event. Today, guardsmen in their scarlet tunics and bearskin caps delivered a display of precision marching on Horse Guards Parade, honed over weeks of practice and part of their ceremonial duties when not fighting soldiers.The national celebration is one of the highlights of the royal calendar and later will feature the Royal Family assembled on Buckingham Palace's balcony for the traditional fly-past of RAF aircraft.The colour – regimental flag – being trooped this year is the King's Colour of the Grenadier Guards presented by the King earlier this week during a Buckingham Palace ceremony and it will be escorted during Saturday's spectacle by guardsmen from the King's Company. The Princess of Wales sat next to her youngest son Prince Louis for the Trooping the Colour parade The Princess was all smiles as she joined the Royal Family for the annual occasion in London The King and Queen attended the birthday parade, riding in a carriage during the eventThe new Defence Secretary Dan Jarvis is expected to be among the spectators with other senior cabinet members, including the Prime Minister, after his predecessor John Healey quit on Thursday over a dispute about long-term funding for the military.The Grenadier Guards were raised in 1656 in Bruges, Belgium, by the exiled King Charles II to protect him during the period Oliver Cromwell ruled England.Charles, Colonel-in-Chief of the Grenadier Guards, visited his King's Company at their barracks in Aldershot on the eve of Trooping and wished them 'great success' for the big day.He told the company: 'Since Easter you've been practising rigidly and I can hear from Buckingham Palace the sound of the drums thumping away regularly so I know you're all marching up and down trying to get ready for the parade.'The King went on to say: '…ever since the last 370 years of your existence you have made us all in this country so incredibly proud of your effort, your service and your sacrifice over all those years and I feel very proud and privileged to be here.'The King's Birthday Parade this year comes exactly one week after the royals gathered in Kemble, Gloucestershire, for Peter Phillips and Harriet Sperling's 'intimate' wedding. Catherine looked the picture of poise as she arrived at All Saints Church in a Roland Mouret £750 dress and Jane Taylor hat, alongside her husband William, 43.The future Queen was met with the sounds of cheers from crowds of well-wishers who had gathered to catch a glimpse of the royal guests. The Prince and Princess of Wales were joined by their children Prince George, Princess Charlotte and Prince Louis for Trooping the Colour Kate looked typically stunning in a blue and white ensemble as she arrived for the occasion The Princess completed her elegant look with a pair of floral pearl earrings The Princess was photographed travelling to the occasion next to Prince George and Princess Charlotte The Princess Trooping the Colour is a military ceremony that dates back to the 18th century and is one of the most high-profile royal events of the year. It is rooted in battlefield custom, when regimental flags, or 'colours,' were trooped in front of soldiers to ensure they could be recognised amid the smoke of combat.This year, the honour of trooping the Colour falls to the Grenadier Guards, the British Army's most senior infantry regiment, which is celebrating its 370th anniversary.This year marks the fourth Trooping the Colour of His Majesty's reign, after the death of Queen Elizabeth on September 8, 2022. Charles attended his first Trooping the Colour in 1951, aged three, riding in a carriage with his grandmother, Queen Elizabeth, The Queen Mother, and his aunt, Princess Margaret. The King first rode in the parade as Colonel of the Welsh Guards in 1975.The Colours being trooped today were presented to The Regiment by The King in the Gardens of Buckingham Palace on Tuesday, 9th JuneTrooping the Colour was once the largest public gathering of royals of the year, with more than 40 members of the Firm jostling for position on the Buckingham Palace balcony during the flypast.Now, the sparse group is made up of working royals only, including the Prince and Princess of Wales, the Princess Royal and her husband, Vice Admiral Sir Timothy Laurence, and the Duke and Duchess of Edinburgh. They will be joined by the Duke and Duchess of Gloucester and the Duke of Kent, now the oldest working royal at the age of 90, while the King's estranged son, Montecito-based Prince Harry and his wife, Meghan Markle, will be notably absent. The daughters of disgraced former prince Andrew, Princesses Beatrice and Eugenie will not attend today's Trooping the Colour, which they last attended in 2022. They were last seen on the palace balcony with the late Queen Elizabeth in 2019, after they arrived at the Horse Guards Parade riding in an open-top carriage accompanied by Eugenie's husband, Jack Brooksbank, and Prince Edward. In the wake of the scandal surrounding Andrew and his ex-wife Sarah Ferguson's friendship with billionaire paedophile Jeffrey Epstein, Beatrice and Eugenie - who is expecting her third child with Jack - have largely kept out of the spotlight. While they were welcomed back into the royal fold for Peter and Harriet's wedding, Beatrice and Eugenie - who are not working members of The Firm - will not attend today's festivities.