Benedict Cumberbatch

Christopher Tietjens

Rebecca Hall

Sylvia Tietjens

Adelaide Clemens

Valentine Wannop

Miranda Richardson

Mrs. Wannop

Roger Allam

General Campion

Rupert Everett

Mark Tietjens

Janet McTeer

Mrs. Satterthwaite

Tom Mison

Potty Perowne

Stephen Graham

Vincent MacMaster

Sasha Waddell

Glorvina

Clare Higgins

Lady Claudine

Tat Whalley

Army Groom

Christine Cox

Mother

Rudi Goodman

Michael (8 years)

Freddie Fox

Edward Wannop

Jack Huston

Gerald Drake

Rufus Sewell

Reverend Duchemin, Edith's husband

Charles Dhondt

British Red Cross soldier (uncredited extra)