The royal couple left their children Prince George, 4, Princess Charlotte, 3, and Prince Louis, 2-months, at home.
Kensington Palace also released the official portraits from the couple's youngest son's royal christening later in the day.
Related: See all the official portraits from Prince Louis' royal christening
Kate was also lucky enough to attend the Wimbledon Women's Finals the day before alongside sister-in-law Meghan Markle.
The Duchess of Cambridge has always been a presence at the famous tennis tournament, regularly attending matches as a child with her family and then as a royal family member with William.
She said of the tournament last year, 'It is such a quintessential part of English summer.'
The duchess has also previously revealed that Prince George is a tennis lover.
Sam Richardson, a coach with the association, told PEOPLE: '[Kate] says with George just being 4 he wants to whack a ball. So, she was asking what sort of stuff should be doing,' Richardson says. 'She said he’s interested in it but more in whacking the ball.'
In the latest instalment of New Idea Royals, the team delve into what REALLY happened at Prince Louis' royal christening. You can subscribe via iTunes http://po.st/Cj1hPZ or OMNY http://po.st/xGvgbw
