The British royal family gathered at Buckingham Palace in London on Tuesday to watch a flypast celebrating 100 years of the Royal Air Force. Prince William and Prince Harry were decked out in their military finest.
At her first royal christening, the former "Suits" actress gave a nod to her USA roots by wearing an olive-toned design by popular American designer Ralph Lauren.
Auntie Meghan kitted herself out in a sophisticated Ralph Lauren dress for the christening of Prince Louis yesterday - and even dug out matching heels and a hat.
"Meghan is known for wearing her hair in a looser and more relaxed style, but her hair today is much sleeker and more elegant, with a very tight ballerina-style knot in place of her usual messy bun".
We have to say, we think the new royal's minimalist look was strikingly similar to the famous black dress that Audrey Hepburn wore in her movie Sabrina.
Brian O'Driscoll and Amy Huberman, who attended Prince William's wedding to Kate Middleton in 2011, were among the guests at the garden party.
The Duke and Duchess of Sussex are also expected to spend time at the Famine Memorial and visit EPIC, the Irish Emigration Museum that tells the story of the 10 million Irish people who have emigrated across the world.
They joined Queen Elizabeth and other members of the royal family early Tuesday morning for the centenary celebration of the Royal Air Force (RAF).
Harry and Meghan's engagements will include official meetings with Taoiseach Leo Varadkar and President Michael D Higgins.