Tilda Swinton
— Gertrude Bell (voice)
Adam Astill
— Sgt. Frank Stafford
Tom Chadbon
— Sir Valentine 'Domnul' Chirol
Simon Chandler
— David Hogarth
Joanna David
— Janet Courtney
Anthony Edridge
— Sir Arnold 'A.T.' Wilson
Amed Hashimi
— Suleiman Faidhi
Andrew Havill
— Sir Percy Cox
Michael Higgs
— General Sir Gilbert Clayton
Hayat Kamille
— Mme. Jamil Zadeh
Rose Leslie
— Young Gertrude Bell (voice)