/ Mammoth Screen
The pair will play charismatic and wayward Foreign Secretary Lord Palmerston and Victoria’s mysterious sister Feodora alongside returning stars Jenna Coleman and Tom Hughes.
In addition, actor and comedian John Sessions (The Loch) will star as Prime Minister John Russell, while Lily Travers (Kingsman) will play the Duchess of Monmouth.
Nicholas Audsley (The White Princess), David Burnett (The Mummy) and Emily Forbes (Endeavour) also join the cast as new characters.
Starting in 1848, the third instalment of the lavish drama will depict a turbulent and uncertain time for both Europe and the monarchy.
With revolutions on the continent and the Chartist movement reaching its peak in London, Victoria is under pressure from the government to leave London for her own safety.
Creator Daisy Goodwin said: “Victoria and Albert are the most famous couple of the nineteenth 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 eight-part series is a co-production with America’s MASTERPIECE and is produced by Mammoth Screen.