The Clooneys Expected to Attend Royal Wedding: Meghan and Amal 'Have Known Each Other for a While'

George and Amal Clooney are among the lucky ones who scored the wedding invite of the year.

The actor and his lawyer wife are among the guests attending Prince Harry and Meghan Markle’s wedding at Windsor Castle on Saturday, a source confirms to PEOPLE.

“Meghan and Amal have known each other for a while,” confirms the source. The insider reveals that the two women were introduced by a mutual friend and have formed a friendship since Meghan moved to the U.K., adding that they share “many interests.”

The source says the Clooneys are also two of the 200 invited to the private evening reception at Frogmore House on Saturday.

The couple — whose twins Ella and Alexander will celebrate their first birthday next month — live just 30 minutes by car from Windsor.

RELATED: Meghan Markle’s Suits Costars Are Wedding Ready in Windsor, Call the Couple ‘a Great Match’

Other expected celebrity royal wedding attendees? Actress Priyanka Chopra, and several of Meghan’s Suits costars — including Gina Torres, Sarah Rafferty and Rick Hoffman, who appeared on Today to discuss the happy couple on Friday.

• Don’t miss out! Tune in to Meghan and Harry – a Fairy-Tale Wedding on Saturday, May 19, starting at 6 a.m. ET/ 3 a.m. PT on PeopleTV — now available on PeopleTV.com and on your favorite streaming device.

With one day to go, Kensington Palace just announced that Meghan, 36, will walk to the altar on her wedding day with her future father-in-law, Prince Charles.

Meghan had planned on having her father, Thomas Markle, by her side, but she “sadly” confirmed on Thursday that he would not be attending the royal wedding as originally planned.

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“Ms. Meghan Markle has asked His Royal Highness The Prince of Wales to accompany her down the aisle of the Quire of St George’s Chapel on her Wedding Day,” the palace statement said. “The Prince of Wales is pleased to be able to welcome Ms. Markle to The Royal Family in this way.”

RELATED VIDEO: See Smiling Meghan Markle Arrive in Windsor with Prince Harry Amid Ongoing Family Drama

For the earlier part of the procession through the Nave of St. George’s Chapel, Meghan will be accompanied by her 10-strong squad of bridesmaids and page boys, which means she will walk down the greater part of the aisle without someone by her side.

Of the plan, a royal source told PEOPLE, “It was Meghan’s wish and she is grateful for the Prince of Wales to be doing it.”