The Duke of Sussex has always shared a close bond with his cousin, Princess Eugenie, but it also extends to her husband, Jack Brooksbank.
Eugenie was one of the first family members whom Prince Harry introduced to his future wife Meghan Markle during a dinner at Nottingham Cottage in 2016.
In an excerpt from his memoir, Spare, released in January, he wrote: "I remember Euge hugging Meg, as if they were sisters. I remember [Harry's friend] Charlie giving me a thumbs-up. I remember thinking: If meeting the rest of my family goes like this, we're home free."
And before Harry and Meghan's relationship was made public, they enjoyed a night out in Toronto with Eugenie and Jack. The foursome went incognito to a post-apocalyptic-themed Halloween party, with Harry and Meghan sharing personal snaps in their Netflix docuseries.
Harry later told of Meghan's love for "Euge and Jack," and even revealed that he and Meghan pushed back their first royal tour by a few days so that they could attend the couple's wedding in Windsor in October 2018.
"Euge was getting married, to Jack, and we were deliriously happy for them and for ourselves, selfishly, since Jack was one of our favourite people. Meg and I were supposed to head off on our first official foreign tour as a married couple, but we delayed the departure several days, so we could be at the wedding."
And when Harry flew over from California to King Charles and Queen Camilla's coronation in London in May, he arrived at Westminster Abbey at the same time as Eugenie, Jack, and his other cousins, Princess Beatrice, Zara Tindall and their husbands.
The Duke was seated next to Jack throughout the service, and was spotted having an in-depth conversation with his cousin's husband, and even confirmed that he would be going "straight to the airport" after the ceremony.
Harry and Meghan's children, Prince Archie, four, and Princess Lilibet, two, are of a similar age to Eugenie and Jack's sons – August, two, and Ernest, who was born in May.
Eugenie flew to the US to see her cousin in 2022, with the pair attending the Super Bowl, playing with Archie on the beach and riding bicycles together, as seen in the Netflix series.