William and Kate took in the swimming at the Sandwell Aquatics Centre, where they were joined by the Earl of Wessex, Vice-Patron of the Commonwealth Games Federation, and his wife Sophie, who have been attending various events throughout the tournament.
WATCH: Princess Charlotte looks so shy as she greets well-wisher in Cardiff
It was a family affair for the Wessexes, who also brought their teenage daughter Lady Louise Windsor and son James, Viscount Severn to the event.
This was the Cambridges' first appearance at the Games and comes shortly after William watched the England women's football team, the Lionesses, clinch victory over Germany at the Euro 2022 final on Sunday night.
William and Kate were joined by Princess Charlotte at the swimming
William and Kate looked delighted to be reunited with Edward and Sophie as they greeted each other with a kiss before taking their seats.
Kate looked so chic in a white blazer and trousers combo
The Duchess was her typically chic self in a white suit that consisted of high-waisted trousers, a top, and a smart blazer. She had her hair styled in loose waves and a side parting.
The mother-daughter duo shared a sweet moment
Seven-year-old Charlotte, meanwhile, looked adorable in a striped summer dress that featured a Peter Pan collar, and white strappy sandals.
Charlotte gave an enthusiastic thumbs-up sign to her dad William
She appeared to thoroughly enjoy herself as she gave an enthusiastic thumbs-up sign to her dad William, and at one point looked surprised as the action unfolded.
The little girl was enthralled by the action
The Wessex family sat behind the Cambridges, with Sophie looking gorgeous in white trousers and a pastel peach printed top. Her daughter Louise, 18, coordinated with the royal in a white blouse and a patterned maxi skirt in similar hues.
The royals greeted each other as they arrived for the swimming
Earlier on Tuesday, Edward, who has been a regular attendee at the Commonwealth Games, was spotted watching the athletics fixtures with his children. The family also enjoyed the weightlifting and swimming events the day before.
The Wessex family also joined the Cambridges at the swimming
The Commonwealth Games, which kicked off on Thursday 28 July, are running until Monday 8 August.
Ahead of the Games, Edward released a heartfelt message, saying: "The waiting is over. The XXII Commonwealth Games is about to get underway and for the next 11 days all eyes will be on Birmingham and the West Midlands of England.
They were seated behind the Cambridges at the Sandwell Aquatics Centre
"To all athletes, officials, spectators and visitors I bid you a very warm welcome and thank you all for coming. It simply wouldn't be the great festival of sport it is without you."
Prince Edward is Vice-Patron of the Commonwealth Games Federation
The Queen's youngest son continued: "Yet the Games are more than just about sport, they are the greatest manifestation of the Commonwealth: our extraordinary collection of countries linked together through a myriad of bonds of common interests and relationships.
"The parallel arts festival is an integral part of this celebration and reminds us of our shared values and the tremendous talent that exists across our family of nations."
William, Kate and Charlotte also stopped by the Team England Futures programme
While in Birmingham, William, Kate and Charlotte also stopped by the Team England Futures programme, which is a partnership between the Duchess' patronage SportsAid, Sport England, and Commonwealth Games England.
The royals arrived to a warm welcome at SportsAid House, where they were introduced to a group of young athletes and support staff who are being supported by the Team England Futures programme.
They were introduced to a group of young athletes and support staff
The programme aims to better prepare budding sports stars to become Team England, Team GB, or ParalympicsGB debutants at future Games.
Charlotte took part in an interactive workshop
It's designed to help participants understand how to perform at their best, how to handle the pressure and distractions associated with major Games, and how to make the most of the experience.
She helped pin medals to the Team England medal board
During this year's Commonwealth Games, around 1,000 talented young athletes and aspiring support staff have been given the opportunity to attend the Games, take a first-hand look behind the scenes, and meet mentors and ambassadors including Olympic, Paralympic, and Commonwealth medalists who have shared advice and knowledge from their own careers.
Before leaving, the royals posed for a group photo
After hearing about the benefits of the programme, the royals also took part in an interactive workshop alongside a group of athletes, where they learnt about the practical advice provided to the sports stars on nutrition and restful sleep.
Tim Lawler, chief executive of Sports Aid, revealed during the engagement: "I did notice the Duke and the Duchess, as we were trying to do, include Charlotte in the conversations – we were very mindful of that and it was really very evident the Duke and Duchess were doing that to, I suppose, include her and reassure her."
Kate became patron of SportsAid in 2013
He added of the Princess: "She was charming, very willing to put the medals on the medal board, and she asked the right question, which was, 'Where exactly should I put this?' It was by date and she checked."
The Cambridges then headed back to watch some more of the Commonwealth Games. They stopped by the University of Birmingham Hockey and Squash Centre where they were reunited with the Wessex family.
The Cambridges reunited with the Wessexes for the hockey
Edward and Sophie looked particularly invested in the England vs India women's hockey game and couldn't help but wear their emotions on their sleeve.
Charlotte was on her best behaviour
Charlotte was on her best behaviour, pictured shaking hands with Games staff and volunteers as she took her seat in the stands in between her parents.
After taking in some of the hockey match, the Cambridges headed to watch Charlotte's favourite sport - gymnastics!
The royals were treated to toy mascots
The royals were seen leaving the venue with mascot toys, with William and Kate holding one each, presumably for Prince George, nine, and Prince Louis, four, who weren't on the family outing.
Charlotte had a ball watching the gymnastics
At Arena Birmingham, Charlotte looked particularly excited to take in the gymnastics and was pictured waving her arms in the arm, dancing and giggling.
The youngster said her favourite sport is gymnastics
Tim Lawler, chief executive of Sports Aid, had previously revealed: "She really, really loved seeing the swimming, but she's interested in the gymnastics, and while they're trying lots of different sports at home, I understand, when I asked her about sport she answered very easily and said, 'It's gymnastics that I like.'"
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