James Purefoy

Thomas Marshall

Kate Mara

Lady Isabel

Jason Flemyng

Becket

Paul Giamatti

King John

Brian Cox

Albany

Derek Jacobi

Cornhill

Charles Dance

Stephen Langton, Archbishop of Canterbury

Aneurin Barnard

Guy

Jamie Foreman

Coteral

Mackenzie Crook

Marks

Rhys Parry Jones

Wulfstan

Vladimir Kulich

Tiberius

David Melville

Baron Darnay

Annabelle Apsion

Maddy

Steffan Rhodri

Cooper

Daniel O'Meara

Phipps

Bree Condon

Agnes

Guy Siner

Oaks

Marcus Hoyland

Abbott Marcus

John Pierce Jones

Cook

Jeff Jones

Head Clerk

Ceri Mears

Blacksmith

Kenneth Collard

Sapper Captain

Wyn Bowen Harries

Baron

Dewi Williams

Baron

John Weldon

Castle Darney Sentry

Laura Sibbick

Castle Servant Girl

Edward Manning

Mercenary

Simon Nader

Hungarian Mercenaries (voice)

Steve Purbrick

Tavern Landlord

Peter Bartfay

Hungarian Mercenaries (voice) (uncredited)

Dan Burman

Mercenary Scout (uncredited)

Ian M. Court

Priest (uncredited)

David Harkus

Young Soldier (uncredited)

Gerald Royston Horler

Hungarian Warrior (uncredited)

Rhys Horler

Hungarian Warrior (uncredited)

Rhi Louise

Topless Wench (uncredited)

Stuart Mager

Garrison Guard (uncredited)

Christian Morgan

Wounded Guard (uncredited)

Stevie Raine

Mercenary Fight Performer (uncredited)

Carlton Venn

King's Aid 2 (uncredited)