Fennell stars opposite Josh O'Connor, who has already been confirmed by Netflix as playing a young Prince Charles, and the pictures of the two actors reveal The Crown is diving into the early days of their forbidden romance.
The scene is one of the more iconic and talked about moments in royal history, where Prince Charles was captured talking to his ex-lover after a polo match in 1975.
The exchange between the pair was heavily discussed at the time, as Prince Charles had split with girlfriend Camilla to undertake his royal duties in the navy and who had then married her first husband Andrew Parker Bowles.
Season 3 of The Crown has a brand new cast with Olivia Colman taking over from Claire Foy as Queen Elizabeth, Helena Bonham Carter replacing Vanessa Kirby as Princess Margaret, and Tobias Menzies replacing Matt Smith as Prince Philip.
This is moving to the top of our must-watch list for 2019.