Duchess Kate pays a royal visit to ‘Downton Abbey’ set

A British royal venturing below stairs? Carson would no doubt disapprove, but that's just what Catherine, the Duchess of Cambridge, did on Thursday in a visit to the set of "Downton Abbey" at London's Ealing Studios.

According to the Twitter account of Kensington Palace, the goal of the visit was to" celebrate the success" of "Downton Abbey," which it described as "one of the UK's greatest cultural exports." The hugely popular drama, which airs stateside on PBS, is now in production on its sixth season. Exteriors and some interior scenes are shot on location at Highclere Castle, while the 113-year-old Ealing Studios is home to the servants' quarters, bedrooms and wardrobe and prop departments.

"We are so honored to have had Her Royal Highness the Duchess of Cambridge join us on the set of 'Downton Abbey,'" said Gareth Neame, executive producer, and managing director of Carnival Films, which produces the series. "The duchess is a great fan of the show, so it was interesting to see her step into the world-renowned sets and see the characters come to life. She was so incredibly gracious to spend time with our actors and those behind the camera who bring the saga of the Crawley family to life.”

While on set, the woman formerly known as Kate Middleton watched a scene being filmed.

PHOTOS: Duchess Catherine with the cast of 'Downton Abbey'

She was also presented with a wooden train for Prince George from the young actor who plays that other George, Lady Mary's son and heir to Downton Abbey.

She posed for a picture with much of the cast, though not Maggie Smith, who was reportedly not feeling well and unable to make it to set, thereby crushing all our dreams of a photo of the dowager and the duchess together. (Though please note that Laura Carmichael was present and, just as her alter ego Lady Edith would be doing, was clinging tightly to young Marigold.)

Ever the clotheshorse, the expectant Kate also checked out the costume department.

The Duchess also shared a conspiratorial laugh with Rob James-Collier, who plays villainous underbutler (just don't call him a footman!) Thomas.

And she even got a cake from Mrs. Patmore, who was no doubt in a state of high consternation in the run-up to the royal visit.

She chatted it up with Michelle Dockery and Joanne Froggatt, in costume as their respective characters Lady Mary and Anna.

According to People magazine, Kate also spoke with Phyllis Logan, who plays Mrs. Hughes, as she sat in the makeup chair. We can only imagine they traded some wedding tips.

Follow @MeredithBlake on Twitter.