The couple got married in 2011, ten years after they met at the University of St Andrews, and they have since welcomed three children: Prince George, Princess Charlotte and Prince Louis. While they don't often show public displays of affection, they do have certain tips and tricks to keep their marriage strong. From their teasing humour to dedicated date nights – with or without children – take a look at the secrets behind the royal couple's marriage…
WATCH: Prince William has best reaction to his royal wedding being a highlight of the past decade
If you're going to spend the rest of your life with someone, you've got to make sure you can laugh and enjoy the good times as well as supporting one another through the tough times.
When the royals announced their engagement in 2010, Prince William said: "Obviously we both have a very fun time together, both have a very good sense of humour about things, we're down to earth, we take the mickey out of each other a lot, and she's got plenty of habits that make me laugh that I tease her about."
William and Kate are often pictured giggling
Kate added that being supportive is also instrumental in helping their relationship blossom: "You know, over the years William has looked after me, he's treated me very well – as the loving boyfriend he is, he is very supportive of me through the good times and also through the bad times."
Support each other
That leads us to secret number two: support. Kate paid tribute to her beloved husband in April 2021 during an open discussion with three parents, whose children attend Roe Green Junior School in Brent, alongside the school's headteacher.
While discussing their experiences of lockdown life, the group was asked: "Who has been the greatest support to you during the pandemic?" and the Princess immediately wrote down William's name. She grinned as she proudly held his name towards the camera and the headteacher said: "That's lovely."
Agree on life decisions
The royals at their engagement photocall in 2010
From relocating to Windsor to moving their children to a new school, the Prince and Princess are no strangers to making new (and sometimes tough) life decisions. One of them was actually deciding when to get married, Prince William explained as he divulged the reason he didn't rush into proposing to his long-term girlfriend.
King Charles III's son said in their engagement interview in 2010: "We've talked about this happening for a while so Kate wasn't in the dark over it all. We've been planning it for a year if not longer, it was just finding the right time. As most couples say, it's all about timing.
"I had my military career and I really wanted to concentrate on my flying, and I couldn't have done this if I was still doing my training. So I've got that out of the way, and Kate's in a good place in terms of work and where she wants to be, and we just both decided that now would be a really good time."
Of having time to consider the responsibilities that come with entering into the high-profile royal family, Kate added: "I'm also glad I've had the time to grow and understand myself more so hopefully I'll do a good job."
Build an equal partnership
There are a lot of things to juggle in a relationship, especially when kids are involved – we're talking cooking dinners for the family, putting the children to bed and doing the school runs.
Although the Wales' do not like to disclose much about their relationship, royal biography Finding Freedom concludes that they have "an equal partnership." Authors Omid Scobie and Carolyn Durand added that William is "involved in every aspect of raising his three children - including school drop-off and pickup, as well as homework".
Maintain your independence
A body language expert said the couple are happy to operate as individuals
While it's great to support one another's interests and build relationships with each other's families and friends, it is also important to maintain your own independence – that's exactly what the royals have done, according to body language expert Darren Stanton.
Following Kate and William's first outing of 2022, Darren, on behalf of Betfair Casino, explained: "One thing that is clear about William and Kate as a couple - and has been from the outset - is that they are undeniably on the same page.
"They are more than comfortable with one another and around each other, so much so that they don’t feel a need to constantly be tactile. This was visible during [their] engagement where they were seen keeping a subtle distance from each other, yet held the exact same posture.
"This can be taken as a show of strength as the pair are happy to operate as individuals despite attending events as a pair. At one point, William was seen leaning closely into Kate to talk to her on a more personal level - a gesture that demonstrates how they are more than happy to have each other in close proximity, alludes to the strengthened rapport between them and suggests they are a very strong couple indeed."
He added that Kate choosing to exit the vehicle on her own while William followed points to "the confidence she and William have in each other’s ability" and demonstrates her "sense of independence within her relationship with William."
Create a close bond with your in-laws
They both have close relationships with one another's family
Meeting the in-laws can be a challenge at the best of times, let alone when your future family members include the late Queen Elizabeth, now-King Charles and Queen Consort Camilla!
Kate supported Her Majesty by attending engagements, going on tours and taking on patronages, and both Kate and William revealed they looked up to the monarch's relationship with the Duke of Edinburgh.
"I'd love to know their secret," William said of his grandparents during a BBC documentary. "I think it’s fantastic and I've regularly asked them both how they've managed it, because they are the most lovely couple. I hope Catherine and I have the same sort of future ahead of us, where we can be as happily married as they are after 68 years."
Kate also said in an interview for ITV's Our Queen at Ninety documentary: "All the time William and I are so struck by the Queen's sense of duty and commitment. And I think to do that by yourself would be a very lonely place to be. But I think to have the support of your husband there by your side on those occasions – and behind closed doors as well – I think is really special.
"William and I have got quite a long way to go. But, no, it really, really is fantastic."
Meanwhile, William said of Kate's family: "I love my in-laws", and James Middleton opened up about his mental health in an op-ed in the Daily Mail, writing: "I want to speak out, and they are my motivation for doing so," referring to Kate, William and Prince Harry.
Date night is important
The Prince and Princess of Wales share three children
William and Kate are rarely apart from their children, even inviting them to the pantomime in London over the Christmas holidays in 2020, but they do spend some quality alone time together.
During their first holiday as a family of five in summer 2018, visiting the private island of Mustique, the royal couple managed to take a night off parenting duty and attend a gold-themed party. Fellow revellers revealed to HELLO! that William and Kate dressed "island chic", and one source said: "They were there for the cocktails segment and kept it rather classy."
However, their children are always keen to join their parents when possible. After the couple attend The Royal Variety Performance in 2019, Kate said they had been really excited about where she and William were going - particularly the dancing and singing - and asked if they could come, but she had to tell them, "Not on a school night!"
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