The bride, who played his character Jon Snow’s lover Ygritte on the HBO show, wore a long sleeve stunning ivory lace wedding dress with floral appliques, a white flower crown, and cathedral veil and carried a bouquet of white roses.
Leslie, who has been with Harington for four years, is a descendant of King Charles II and the 12th-century castle, which is now a popular wedding venue and private hotel, has been owned by her family for the past 900 years.
Guests cheered and tossed confetti on the happy couple as they made their way back up the aisle and drove off in a Land Rover adorned with “Just Married” signs en route to a reception on the castle grounds.
“We are absolutely thrilled for Kit and Rose to be marrying today,” Leslie’s father Sebastian Leslie told reporters before the ceremony.
“It’s an absolutely lovely day for us,” he added.
Family and friends attended the private ceremony, including Game of Thrones stars and other celebs.
Sophie Turner and Maisie Williams arrived together in matching black and red ensembles. Peter Dinklage and Emilia Clarke were also in attendance for the nuptials.
While the couple has kept their off-screen romance on the private side, news of their wedding date and engagement were first revealed through local media.
Back in September, the couple’s official announcement was made in The London Times.
“The engagement is announced between Kit, younger son of David and Deborah Harrington of Worcestershire, and Rose, middle daughter of Sebastian and Candy Leslie of Aberdeenshire,” the announcement read.
Although the twosome didn’t make their red carpet debut as a couple until the Olivier Awards in April 2016, both Kit and Rose have expressed their love for each other at special times in their relationship.