Well, that’s one celebrity we weren’t expecting to see!
Moore was seen arriving at Windsor Castle ahead of the ceremony. The actress stunned in a maroon dress with a matching fascinator.
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After the wedding ceremony, the newlyweds will also be feted by a lunch hosted by Queen Elizabeth Windsor Castle and then a black tie evening reception at Royal Lodge.
Eugenie and Jack are also extending the party for another full day with a festival-style event complete with a fairground and food stalls on Saturday.