Actors Laurence Fox and Kate Fleetwood are to join the cast for the third series of historical drama Victoria.
ITV has confirmed that filming has begun for the recommissioned programme, which chronicles the reign of Queen Victoria and her marriage to Prince Albert.
The new eight-part series will begin in 1848, during a time of uncertainty for the monarchy.
Victoria is under pressure from the government to leave London for her own safety as the Chartist movement reaches its peak.
Doctor Who star Jenna Coleman will reprise her role as the young Queen Victoria alongside Tom Hughes as Prince Albert.
Fox, who appeared in Inspector Morse spin-off Lewis from 2006 to 2015, has been confirmed to play Foreign Secretary Lord Palmerston.
Tony and Olivier Award nominee Fleetwood will play Victoria’s sister Feodora, who will make an unexpected return to the Queen’s life.
Comedian John Sessions will feature as Prime Minister John Russell and Kingsman star Lily Travers will play the Duchess of Monmouth.
Speaking about the programme’s next instalment, creator Daisy Goodwin said: “Victoria and Albert are the most famous couple of the 19th century but, underneath the united facade, their relationship is at breaking point and it is a struggle for mastery that neither side can win.”
The first series of Victoria drew ITV’s highest ratings for a drama in 2016 and the second attracted a consolidated average of 6.4 million viewers.
The programme has also been aired in the US on the PBS network, where it reached an average audience of 5.2 million viewers.
ITV Studios Global Entertainment has sold Victoria to a total of 189 countries worldwide.