The Prince and Princess of Wales are the most notable couple within the Royal Family. Having been married since 2011 and parents to three children, their bond is as robust today as it was on their wedding day at Westminster Abbey.
Today, Kate Middleton celebrates her 43rd birthday following a hectic year. The Princess has now finished her cancer treatment and relocated with her family from Adelaide Cottage to Forest Lodge in Windsor.
However, the early stages of their relationship were far from smooth sailing. For William, a future king navigating a romance under intense public scrutiny was challenging - he reportedly once upset his future wife by cancelling an important date.
Before they tied the knot, Royal protocol dictated that William and Kate would spend Christmas apart; he would join the wider Royal Family at Sandringham, while she would head back to Bucklebury to be with her parents and siblings. In 2006, the couple planned to celebrate New Year's Eve together as a compromise.
However, William had a change of heart at the last minute, leaving Kate uncertain about the future of their relationship, reports the Mirror.
In her book, The Making of a Royal Romance, Royal biographer Katie Nicholl suggests William had initially agreed to spend time with Kate's family but chose to stay with the Royals instead - delivering the news to her by telephone on Boxing Day, according to the Mirror.
Katie wrote: "William had been having second thoughts and sat down with his father and his grandmother to have a frank discussion about his future with Kate. Both advised him not to hurry into anything."
In 2007, just weeks after Prince William called off his New Year's Eve arrangements with Kate and her relatives, he brought their relationship to an end. Thankfully, the pair reunited and rekindled their romance within months.
They have stayed together ever since, announcing their engagement in 2010 before marrying in 2011. The Royal pair have gone on to have three children: Prince George, Princess Charlotte, and Prince Louis.
William revealed the depth of his feelings for his wife Kate through a telling comment that highlights their connection, according to one observer. The Prince of Wales was visiting the Youth Shedz organisation in North Wales, where he spoke with the group's founder, Scott Jenkinson, and his wife Sian.
William and Scott formed an instant rapport and spoke about the importance of having strong support in one's life. "Were you there with Scott when he turned his life around?" William asked Sian, after hearing about Scott's previous experiences with homelessness and addiction.
"He has done well to turn his life around."
Sian replied: "He has, he really has," with Scott chiming in: "With my wife behind me. You know that."
As William approaches his 15th wedding anniversary with the Princess of Wales, he acknowledged with a nod: "This is it. Behind every average man there is an even better wife."
Former BBC Royal correspondent Jennie Bond offered her perspective to the Mirror: "I thought it was a sweet comment, which showed just how equal their partnership is, and how much William values Catherine's support and advice in everything he does. We women also know that it is absolutely true!".
"Men are brilliant in so many ways, but it really is almost always the woman of the house who juggles a million balls to keep everyone on track, on time, properly kitted out and happy. I'm sure Catherine is no exception. And good on William for acknowledging this universal truth!".
The Prince and Princess of Wales go to great lengths to protect their three children from the public eye and maintain privacy around their family life. Yet, William recently provided a glimpse into their daily routine at home, demonstrating how hands-on both he and Catherine are as parents.
Speaking to Luciano Huck for Brazilian television, he remarked with a grin: "I'm the taxi driver, Luciano. Taxi driver, sports days, matches, playing in the garden, where I can. School run, most days. I mean, Catherine and I share it. She probably does the bulk of it."