It's the biggest celebrity wedding of the year, if not the decade, and for a star known for her love of surprises, Taylor Swift is expected to serve up plenty.
But perhaps the most unexpected moment of the wedding weekend so far, as guests gathered to celebrate the nuptials in New York, was Prince William's appearance on Travis Kelce's New Heights podcast.
Forget tea on the White House lawn: Prince William's Fourth of July weekend moment shows a very fresh approach to protecting the special relationship with the US: less traditional diplomacy, more shared pop culture.
For all the rumours that he and Catherine would visit America to mark today's 250th anniversary of independence, a formal invitation never materialised.
Given King Charles's stellar handling of April's state visit, their presence wasn't needed.
Friendship with pop royalty
But William's latest move perhaps says more about how he plans to build bridges between the two nations moving forward - by being himself and appealing to the next generation.
Discussing touchdowns, barbecues, and the "good brotherhood" between the two nations on one of the world's biggest podcasts will likely do far more to cement positive relations than lining up to press the flesh with politicians and officials.
It's a moment that's been more than a decade in the making. William's friendship with Taylor began in 2013, when he found himself singing alongside her and Jon Bon Jovi on stage at a fundraiser for the homelessness charity Centrepoint.
Later admitting he still cringed at the memory, he said: "But frankly, if Taylor Swift looks you in the eye, touches your arm, and says 'Come with me…' I got up like a puppy and went, 'Yeah, okay, that seems like a great idea. I'll follow you.'"
© Dave J Hogan/CentrepointThe future King stayed in touch with the Queen of Pop and one of my favourite memories of William is seeing him shamelessly dad-dancing during the Eras Tour at Wembley Stadium, having introduced Prince George and Princess Charlotte to the singer and Travis backstage.
It was his 42nd birthday and just four months on from his wife Catherine's cancer diagnosis. He could be forgiven for needing to let off steam, appropriately enough, to Shake It Off.
It was an experience that meant the world to his children. Charlotte in particular is "obsessed" with Taylor, according to her father, who recalled: "The atmosphere was so incredible, you could actually feel the floors shaking when they were all dancing. So it was brilliant, brilliant."
© Kensington PalaceSpeaking to Heart FM last month, he joked that "there might be an invitation around" to her wedding to Travis.
But while he and the family aren't among guests in New York this weekend, William's appearance on New Heights is quite the wedding gift to the couple.
The episode was actually recorded in mid-June. It's release, however, has been timed for the eve of the July 4 celebrations.
Breaking America
But why New Heights, and why now?
Travis's podcast, which he presents with his brother and fellow NFL star Jason, is consumed by millions of Americans thanks to its blend of football fandom, celebrity culture and general banter.
For William, it's a very direct route into a younger, broader US audience – one he might never reach through an official speech or engagement.
The Prince has appeared on a sports podcast before - he opened up about mental health and his love of spending time watching football on That Peter Crouch podcast in 2020. He and Catherine later joined Princess Anne in an episode of Mike Tindall's The Good, The Bad and The Rugby in 2023.
So it's far from a first for the future King. But New Heights is on a very different scale. This is a British royal stepping into an American pop-culture conversation at the very moment it is dominated by Taylor and Travis's wedding.
It takes his recent willingness to share more of his personality with the public to a whole new level.
For a Prince whose role is rooted in history, it's a fascinating new type of diplomacy. William is proving he has a finger firmly on the pulse of present culture and knows exactly when to join the conversation.
