In the build up to the new episodes, HBO in America will air a 15-minute Game of Thrones Ice and Fire: A Foreshadowing behind-the-scenes featurette on February 9. A 30-second teaser for the preview has been released.
Watch the trailer for Game of Thrones Ice and Fire: A Foreshadowing:
Game of Thrones Ice and Fire: A Foreshadowing will have a mix of clips from upcoming episodes, behind-the-scenes-footage, interviews with talent, and cast members' answers to questions posed by fans.
Season four premieres in the US on April 6. It airs in the UK one day later on Sky Atlantic.
New cast members in season four include Mark Gatiss (Sherlock), Joel Fry (Trollied, Plebs), Roger Ashton-Griffiths (Gangs of New York), Indira Varma (What Remains, Luther) and Pedro Pascal (Homeland, The Good Wife), who will play Prince Oberyn Martell - aka The Red Viper.
The new run will also feature guest directors Michelle MacLaren (Breaking Bad, The Walking Dead), Alex Graves (The Newsroom, Fringe) and Neil Marshall (season two's 'Battle of Blackwater' episode).