Flora Ogilvy is joining the cast of Downton Abbey. Credit: Carnival Film & Television

The cast of Downton Abbey is getting a taste of royalty! Flora Ogilvy, 45th in line to the throne and the granddaughter of the Queen's cousin, Princess Alexandra of Kent, is joining the popular TV series.

According to U.K.'s Daily Express, the 18-year-old will be an extra in the upcoming season and has already filmed with Maggie Smith (who plays Dowager Countess of Grantham) and Hugh Bonneville (Earl of Grantham on the show).

"There’s a lot of excitement among the royals and they will almost certainly be watching the new series now," an insider told the Daily Express. "Everyone’s really proud of Flora for bagging a role in such a big show at such a young age and for doing it off her own back."

Another added, "Flora has made a good impression during her time on set, so there’s a good chance she’ll get asked back for future series."

Downton Abbey's season four will premiere in the U.K. this fall -- with reported fans Prince William and Kate Middleton sure to be watching, but won't return to the United States until January 5.