The important reason Kate and William will miss Lilibet Diana's birthday on Platinum Jubilee weekend

Prince William and Kate Middleton travel to Wales in celebration of the Platinum Jubilee on June 4, which just so happens to be Lilibet Diana's first birthday. 

• Prince William and Kate Middleton are unlikely to attend the birthday party of Prince Harry and Meghan Markle's daughter, which will reportedly take place at Frogmore Cottage on June 4. 
• The Duke and Duchess of Cambridge are scheduled travel to Wales on the same day as Lilibet Diana's first birthday. 
• In other royal news, Queen's favorite cocktail revealed by Tom Hanks - a James Bond classic with a different kind of twist.
  

Prince William and Kate Middleton will travel to Wales on June 4 to assist with some last-minute preparations for a Platinum Jubilee Concert at Cardiff Castle in honor of the 70th anniversary of Her Majesty's reign, Buckingham Palace has confirmed. 

The exciting engagement coincides with the first birthday of Prince Harry and Meghan Markle's daughter Lilibet Diana, who will reportedly be celebrating the special occasion at Frogmore Cottage with her parents and older brother, Archie. Royal sources have also said that the Queen is to meet Lilibet on Saturday, following news that the 96-year-old monarch would no longer be attending the Epsom Derby due to her ongoing mobility issues. 

It remains unknown whether or not William and Kate will make it back in time for the Sussex party, but with its venue by Windsor Castle being 130 miles away from Cardiff, it looks unlikely they'll be able to squeeze this one in. 

During their Welsh trip, the royal couple will meet with the performers and crew of the concert, including hosts Aled Jones, Shan Cothi, and Bonnie Tyler. They'll also receive a rundown on the "technical production underpinning the show" including its "lighting, sound and visual effects." The concert's musical performances are expected to wrap up by 7pm, at which point the BBC's Platinum Party at the Palace will be broadcast on oversized screens at the castle. 

The exciting engagement is likely to pique the interest of the musically gifted Kate Middleton, whose piano performance at a Christmas carol service last year wowed royal fans.

The Cambridges aren't the only senior royals with travel plans over the Queen's Platinum Jubilee. 

Prince Edward and Sophie Wessex will fly over to Northern Ireland this weekend for Jubilee-themed arts and crafts and a meet-and-greet with kids involved in multicultural street performances, while Princess Anne will head to Scotland to visit Edinburgh Zoo and the HMS Albion.