Stephen DillaneViscount Halifax
Lily JamesElizabeth Layton
Ronald PickupNeville Chamberlain
Nicholas JonesSir John Simon
Samuel WestSir Anthony Eden
Richard LumsdenGeneral Ismay
Malcolm StorryGeneral Ironside
Hilton McRaeArthur Greenwood
Benjamin WhitrowSir Samuel Hoare
Joe ArmstrongJohn Evans
Adrian RawlinsAir Chief Marshal Dowding
David BamberAdmiral Ramsay
Paul LeonardAdmiral Dudley Pound
Eric MacLennanTom Leonard
Philip Martin BrownSawyers
Jordan WallerRandolph Churchill
Alex ClatworthyDiana Churchill
Mary AntonyMary Churchill
Bethany MuirSarah Churchill
Anna BurnettPamela Churchill
Jeremy ChildLord Stanhope
Brian PettiferLord Kingsley Wood
Michael GouldLord Londonderry
Paul RidleyHouse of Commons Speaker
Robin PearceErnle Hastings
Michael BottEquerry
Olivier BrocheReynaud
Mario HacquardDaladier
Pip TorrensBBC Producer
Edmund WisemanActor
Hannah SteeleAbigail Walker
Nia GwynneAlice Simpson
Ade Dee HaastrupMarcus Peters
James EelesMaurice Baker
Flora NicholsonJessie Sutton
Roisin O'NeillAgnes Dillon
John LockeOliver Wilson
Jo NearyMargaret Jerome
Richard GloverBrigadier Nicholson
Tom AshleyRamsay Staffer
Joshua HiggottReporter
Imogen KingTeenage Girl at Tube Map
Miles GallantNaval Map-Room Officer
Faye MarsaySybil
John AtterburySir Alexander Cadogan
James HarknessAD Nicholl (Secretary #1)
Joshua JamesW D Wilkinson (Secretary #2)
Charley Palmer RothwellChristopher Wilson (Photographer)
Patsy FerranMaid
Sarah FlindCook
Steffan DonnellyBack Bencher
Kieran BuckeridgeCecil Beaton
Johnny OttoMember of Parliament (uncredited)
Nick Howden-SteenstraSentry (uncredited)
