'Unfair' to criticise William and Kate for missing Lilibet's birthday party: 'Shows their dedication to duty'

Criticism towards the Duke and Duchess of Cambridge for missing Lilibet's first birthday party is "unfair", a royal commentator believes.

Prince William and Kate were called out by some for not being at Frogmore Cottage for the party on Saturday June 4, during the Queen's Platinum Jubilee celebrations.

Prince Harry and Meghan had returned to the UK for the Jubilee which coincided with their daughter's birthday.

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On the day the party was held in the grounds of Frogmore the Cambridges had travelled to Wales for a Jubilee-related event.

They took Prince George, eight, and Princess Charlotte, seven, meaning they were not able to be at their cousin's party.

But British journalist Jonathan Sacerdoti says that decision "wasn't a snub".

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Instead, the Cambridges were simply "fulfilling their duties".

The engagement in Cardiff was the first time George and Charlotte had gone there in an official capacity and marked a big step in their future royal careers in support of the monarch.

It was completely understandable for the Cambridges to miss Lili's party, Sacerdoti says.

"They had other engagements, they were in Wales fulfilling their duties as still working royals, during the Jubilee celebration long weekend," he told the Royally Us podcast.

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"So I think it was not really fair to expect them to attend a private birthday party, even of William's brother's daughter."

Photos from Lilibet's party were shared a few days later by Prince Harry and Meghan, once they had landed back in California.

In a statement via their spokesperson the Duke and Duchess of Sussex said they celebrated Lili's birthday in a "casual, intimate backyard picnic" with close friends and family.

Among the guests were photographer Misan Harriman, who took the photos of Lili, and his wife and their children.

William and Kate's absence was noted by many commentators and royal watchers especially as it came just one day after the Sussexes and Cambridges had no interaction at a Service of Thanksgiving.

Sacerdoti says their decision to miss the party would have been out of their hands due to prior commitments in their diary, likely to have been made weeks before Harry and Meghan decided to return to the UK.

"I think that just shows their dedication to duty and service, following the rules that are there for them in their role," he says.

"And their sense of responsibility, and I don't think it's fair to criticise them for not having been there."