Prince Archie turns four years old on 6th May, incidentally the same day as his grandfather the King's coronation.
Sadly, this means that his dad Prince Harry will miss his actual birthday, but meanwhile his mum Meghan Markle will be there with him for this milestone, as will his sister Lilibet.
However, it sounds like the little boy's birthday party might take place on a different day, so that he can celebrate with his dad too. But who might the guests include? We imagine some of Archie's school friends will be there, but one public relations expert says we can most likely expect some big names to be in attendance as well.
"There's no doubt there will be famous friends at the party. The couple live in Montecito, which means they have a number of celebrity neighbours," explained Mayah Riaz, speaking to the Mirror.
"Just as we would invite our neighbours to parties, if we were friendly with them, it's the same for the Duchesses.
"We can probably expect Ellen DeGeneres and Portia de Rossi at the party, as the [Sussexes] were at their vow renewal.
"We know the couple are friends with Serena Williams, Priyanka Chopra, and Jameela Jamil to name a few and it's possible if they were around they would be attending."
Mayah also reckons we might see Orlando Bloom pop by — though maybe not, considering his partner Katy Perry will be over in the UK performing at the coronation.
The expert also compared Archie's big day to his sister's first birthday last year, which fell during the Queen's Jubilee weekend.
"If Lilibet's first birthday is anything to go by, we can possibly expect an intimate outdoor picnic amidst the couple's chickens, face painting, a classic birthday cake and surrounded by friends joining throughout the day," she said.
After many deliberations, the Duke of Sussex decided to attend his dad's coronation without his wife and children, but will be departing the UK as quickly as he can — reportedly missing the coronation concert on 7th May so he can be with his newly four-year-old son.
