It is believed that Prince Harry and Meghan Markle invited Prince William and Kate Middleton to Lilibet's birthday gathering as an olive branch. However, the Cambridges missed the event because of a Jubilee engagement.

The Duke and Duchess of Sussex celebrated their daughter's first birthday on June 4 at Frogmore Cottage with a few close friends and family. They had a picnic complete with face painting, balloons, and entertainment for the children.

Unfortunately, Lilibet's first cousins Princess Charlote and Prince George were not there. They accompanied Prince William and Kate Middleton to Cardiff, Wales for a pre-scheduled engagement as part of the Platinum Jubilee celebrations.

According to a Page Six source, Prince Harry and Meghan Markle made certain to invite the Duke and Duchess of Cambridge and their children, but the latter reportedly declined the invitation because of the alleged rift between the brothers. The source claimed that "things are still fraught" between them.

"William is still wary of spending any time alone with Harry as you never quite know what may be reported back afterwards," the royal insider claimed.

Instead, the Cambridges, along with Prince Charles and Camilla, and Queen Elizabeth II, sent their birthday greetings to Lilibet on Twitter.

However, royal author Victoria Arbiter was quick to dispel the claims. She wrote on Twitter, "Buckingham Palace announced on May 30 that the Duke & Duchess of Cambridge would be in Wales on June 4. The visit will have been planned long before then."

However, one netizen wondered why the Duke and Duchess of Cambridge did not let Prince George, Princess Charlotte, or Prince Louis for that matter, join their cousin's birthday party. The royal follower commented, "Is that why the Cambridges took their kids as well to Wales, rather than allow them to meet their cousins? It's their choice either way, I just wish we'd be honest & stop pretending any 'engagement' prevented attendance. It's such a ridiculous lie. We're smarter than that, clearly."

Regardless of Prince William and Kate Middleton's absence, Prince Harry and Meghan Markle still had some of the royal children at Lilibet's party. It is understood that Zara Tindall's three daughters and Mike Phillips' children were there.

Prince Harry and Meghan Markle's child Lilibet
Prince Harry and Meghan Markle's daughter Lilibet Diana Mountbatten-Windsor on her first birthday at Frogmore Cottage on June 4. Photo: Reuters / MISAN HARRIMAN/ Reuters / MISAN HARRIMAN/