The Duke of Sussex has been open about his strained relationships with members of the royal family, however, there was a time when he once shared a close bond with his sister-in-law, the Princess of Wales, over the years.

The pair have known each other since they were teenagers with Kate having met Harry's brother, Prince William, while they were studying at the University of St Andrews.

As a royal girlfriend, she joined her future husband William on family holidays with King Charles and Harry. And at the Order of the Garter ceremony in Windsor in 2008, Harry made sure that Kate felt at ease at such a public outing by making her laugh.

When William and Kate announced their engagement in 2010, Harry was delighted for the pair, telling German newspaper Bild: "I've always wanted a sister and now I've got one. I've known Kate for years, and it's fantastic that she is becoming part of the family."

Take a look at Prince Harry and Kate's sweetest photos together in HELLO!'s gallery…

At the Thanksgiving service to mark the Queen's Diamond Jubilee in 2012 at St Paul's Cathedral, the then-Duchess appeared to get the giggles when her brother-in-law leaned in to whisper to her.

The royal family played a huge role in supporting Team GB at the London 2012 Olympics, and an excitable Harry and Kate, along with William, watched the Olympic torch relay outside Buckingham Palace.

When William, Kate and Harry shared a joint household, they would often carry out engagements together. One of our favourite events was when the trio visited the Harry Potter film set at Warner Bros. Studios in 2013. They laughed as they played with wands during their tour.

The Princess was also pregnant with her eldest child, Prince George, at the time, and Harry has previously spoken about his love for his nephews, George and Prince Louis, and niece, Princess Charlotte, telling The Daily Mail: "They are the most amazing things ever."

We wonder what Harry said to his sister-in-law to make her giggle so much on the balcony of Buckingham Palace as they attended Trooping the Colour in 2014. The pair often share a carriage in the procession, usually with Queen Consort Camilla, and then later with Harry's wife Meghan Markle.

William, Harry and Kate were all hysterical with laughter as they tried 'welly wanging', with children and representatives from charities and Aardman Animations, during a meeting of the Charities Forum at BAFTA in 2015.

Prince Harry was just weeks away from becoming a father for the first time in April 2019 when he joined Kate at the Anzac Day service. The pair stepped out together for the service, chatting and laughing as they arrived at Westminster Abbey.

In the end, when relationships were already broken, Kate was seen walking with Harry towards Windsor Castle following Prince Philip's funeral in April 2021. At the time, their reunion went viral as it appeared Kate was trying to be a bridge between the two brothers.

Over a year later, shortly after the Queen's death, the Prince and Princess of Wales made an appearance in Winsdor and were surprisingly reunited with Prince Harry and Meghan Markle for the emotional outing. Harry and Meghan joined the pair after the Prince of Wales personally extended an invitation to them. Crowds broke into applause seeing the royals couples together with William, Kate and Meghan shaking hands with members of the public.