Daniel Radcliffe as John Kipling

David Haig as Rudyard Kipling

Kim Cattrall as Caroline Kipling

Carey Mulligan as Elsie Kipling

Julian Wadham as King George V

Robbie Kay as Arthur Relph

John-Paul Macleod as Ralph

Bill Milner as Peter Carter

Michael McElhatton as Leo Amery MP

Martin McCann as Bowe

Brian de Salvo as Field Marshal 'Bobs' Roberts

Ciaran Nolan as Daly

Laurence Kinlan as Doyle

Nick Dunning as Colonel Ferguson

Peter Gowen as H.A Gwynne

Richard Dormer as Corporal John O'Leary

Rúaidhrí Conroy as McHugh

Simon Coury as Naval Doctor