Royal fans have some monikers for Prince William, Kate Middleton, Meghan Markle and Prince Harry.

The Duke and Duchess of Cambridge, Prince Harry and Markle are scheduled to attend an event together by the end of the month as the palace announced. Their fans are already excited to meet all the four of them and are giving the four new names.

Lately, Prince Harry's royal engagements are with his fiancée, Markle. But before the "Suits" star and the Duke started dating, there was Prince William, Middleton and Prince Harry dubbed as the royal trio.

With the "Horrible Bosses" officially joining the family soon, the royal trio becomes four. Fans have started making names for Prince William, Middleton, Markle and Prince Harry when all four are together.

"Let the new 'fab four' begin! Can't wait!" Louis commented on Kensington Palace's announcement.

"The millennial four!!!" user @kalica24 wrote.

"The fantastic four," nibomais wrote.

Most of the fans couldn't help their excitement to see all four together. One even asked if it's the first time for Prince William, Middleton, Prince Harry and Markle to share the same stage together.

"looking forward to seeing the four of them interact together on stage. is this the first time this has happen since the engagement?" Terri Holm asks.

"So excited for the 4 of them, I can wait to see Prince Harry and Ms. Meghan they are just very sweet nice and caring," Noemi added.

"They're the best! " Sandy Tungdim wrote.

For Prince William, Middleton, Prince Harry and Markle's first official joint engagement together, they will attend the first annual Royal Foundation Forum on Feb. 28. The theme for the upcoming event where the four is set to attend is "Making a Difference Together."

The gathering will showcase the different programs run by Royal Foundation. Prince William, Middleton, Prince Harry and Markle are also expected to talk about the different projects they are working on as well as their plans for the future.

Markle, Prince Harry, Middleton and Prince William were first spotted together on Dec. 25 when the "Horrible Bosses" star joined the royal family for their traditional morning service on Christmas Day. However, there hasn’t been an official royal engagement for the four other than the one scheduled at the end of the month.

Markle's first Christmas with Prince Harry turned well. But her hat during the morning service received an intense backlash. Some even likened it to a rude emoji and others to a chocolate. Some also considered it a fashion faux pas.

Meanwhile, Prince William and Middleton showed a rare PDA on the same day when they held each other's hands on their way to attend the Christmas church service. The Duke and Duchess of Cambridge rarely touch each other in public, so when they do, their fans immediately notice it.