Other members of the family including the Prince of Wales, Duchess of Cornwall, Duke of Cambridge, Duke of York, and Duke and Duchess of Sussex attended a reception at Buckingham Palace where they mingled with RAF veterans, serving personnel and their families.
The celebrations Tuesday marked the second event in a busy week for Britain's royals, following Monday's christening and ahead of the Queen's meeting with US President Donald Trump at Windsor Castle on Friday. According to sources, when the Royal Family greeted the Archbishop of Canterbury he was pleased to see Louis looking, "very relaxed and peaceful".
Attending the RAF 100 ceremonies was especially poignant for Kate, as she is the Honorary Air Commandant of the Royal Air Force Cadets.
Meghan wore a long-sleeved, full-skirted black Dior dress with a bateau neckline, topped off with a Stephen Jones fascinator.
For the christening of George, Kate and Will's first born, in October 2013, Kate again wore a cream Alexander McQueen coat-dress, this one with a large ruffle down the center of her chest and on her waist.
Nicholas Van Cutsem, Harry Aubrey-Fletcher, and Guy Pelly are Prince Louis' godfathers.
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Cuomo says Monday that the GOP-led Senate should immediately reconvene to pass the measure in light of a vacancy on the U.S. As for what he says about NY law being tougher on abortion than Roe , that's marginally true.
It is a replica of the dress made for Queen Victoria's eldest daughter in 1841.
In a video, the Duke of Cambridge can be seen sitting alongside wife Kate Middleton-who broke her maternity leave for a surprise appearance at the event.
Princess Charlotte wore a blue, flowered dress, while brother Prince George, who turns five later this month, was outfitted in a white shirt and blue shorts.