The Winter King — release date, cast, plot, new pictures, trailer and everything we know

Arthur (Iain De Caestecker) in a leather tunic alongside Merlin (Nathaniel Martello-White) in a white tunic in The Winter King.
Arthur (Iain De Caestecker) and Merlin (Nathaniel Martello-White) face turmoil and danger in The Winter King. (Image credit: ITV)

The Winter King takes a powerful and gritty look at the world of legendary warrior Arthur.

The thrilling 10-part drama, starring Iain De Caestecker as Arthur, is airing on ITVX from Thursday December 21 in the UK and is set in Britain during the Dark Ages of the 5th century. It is an adaptation of the Warlord Chronicles trilogy of books by Bernard Cornwell, who is best known for his Sharpe novels, which were turned into a long-running drama starring Sean Bean.

The Winter King is rooted in the reality of what it might have been like in that time period and it’s a grounded, human version of the legend," says De Caestecker. "You've got the well-known characters, but with a different slant on them. We go into Arthur's earlier backstory and he becomes a forward-thinking leader.”

Here’s everything we know about The Winter King

Iain De Caestecker as Arthur on a horse in The Winter King.

Arthur (Iain De Caestecker) must fulfil his destiny in The Winter King. (Image credit: ITV)

The Winter King release date

The drama will air from Thursday December 21 on ITVX and it will be available on ITV1 at a later date. In the US, it is streaming now on MGM+.

Arthur (Iain De Caestecker) in a dark tunic stands before King Uther (Eddie Marsan) in a blue robe in The Winter King.

Arthur (Iain De Caestecker) and Uther (Eddie Marsan) have a difficult relationship in The Winter King. (Image credit: ITV)

The Winter King — what is the plot?

The series, adapted by Kate Brooke (Bancroft, A Discovery of Witches) and Ed Whitmore (Silent Witness, Manhunt), centres on courageous Arthur Pendragon (Iain De Caestecker), the exiled, illegitimate son of powerful monarch King Uther, played by Eddie Marsan. 

Outcast Arthur tries to make his way in the world as he becomes a fearsome warrior and respected leader. But he faces challenges because Britain is divided into various tribes and factions and rivalries are often bloody and deadly. Meanwhile there are also threats from invading Saxons as well as clashes between Druids and Christians.

The Winter King — who is in the cast?

Iain De Caestecker (The Control Room, Agents of S.H.I.E.L.D) heads the cast as Arthur, who has to prove his worth and try to save Britain from destruction, while Eddie Marsan (The Thief, His Wife and The Canoe, Deceit) is his father, Uther, High King of Dumnonia, who rules with an iron fist. Nathaniel Martello-White (Small Axe, I Hate Suzie) is enigmatic Merlin, who has both political and spiritual power and is the only person who doesn’t fear Uther.

Derfel (Stuart Campbell) and Nimue (Ellie James) in brown tunics look into the distance in The Winter King.

Young warrior Derfel (Stuart Campbell) and priestess Nimue (Ellie James) cross paths with Arthur in The Winter King. (Image credit: ITV)

Ellie James (Giri/Haji, I May Destroy You) is priestess Nimue, who is under Merlin’s protection and has the ability to communicate with the gods. Stuart Campell (SAS Rogue Heroes, Clique) is Derfel, who becomes an intrepid warrior. Olumide Olorunfemi (Venom: Let There Be Carnage) is Derfel's childhood friend Lunete.

Stuart Campbell and Olumide Olorunfemi on horseback in The Winter King.

Derfel (Stuart Campbell) and Lunete (Olumide Olorunfemi) are life-long friends in The Winter King. (Image credit: ITV)

Guinevere (Jordan Alexandra) in a green dress and Ceinwyn (Emily John) in a red dress greet Arthur (Iain De Caestecker) in a fur cloak in The Winter King.

Guinevere (Jordan Alexandra) and Ceinwyn (Emily John) bring fresh complications for Arthur (Iain De Caestecker) in The Winter King. (Image credit: ITV)

Daniel Ings (The Gold, I Hate Suzie, The Crown) co-stars as Arthur’s friend Owain, while Valene Kane (The Fall, Gangs of London) is Arthur’s pagan half-sister Morgan.

Daniel Ings is wet and dishevelled as Owain in The Winter King.

Owain (Daniel Ings) is Arthur's close friend in The Winter King. (Image credit: ITV)

Valene Kane on a horse as Morgan in The Winter King.

Arthur's sister Morgan (Valene Kane) spells trouble in The Winter King. (Image credit: ITV)

Also look out for Jordan Alexandra (Mammals) as Guinevere, the shrewd Princess of Henis Wyren, alongside Simon Merrells (Good Omens, Knightfall) as ruthless Gundleus, the king of Siluria and Tatjana Nardone (Devils, State of Consciousness) is Gundleus’ lover Ladwys.

Steven Elder (The King, A Spy Among Friends) as Bedwin, the caring Bishop of Dumnonia and Andrew Gower (Outlander, Carnival Row) as Sansum, his novice. Aneirin Hughes (Keeping Faith) is Gorfydd, the leader of Powys, Emily John (My Policeman) is Powys’ princess Ceinwyn, Ken Nwosu (Killing Eve, The Letter for the King) is Arthur’s comrade in arms Sagramor alongside Matt Mella (Trigger Point) as Lanval, and Billy Postlethwaite (Chernobyl) is warrior king Cadwys.

Ken Nwosu as Sagramor, Iain De Caestecker as Arthur and Matt Mella as Lanval on horseback in The Winter King.

Sagramor (Ken Nwosu) and Lanval (Matt Mella) are the comrades in arms to Arthur (Iain De Caestecker) in The Winter King. (Image credit: ITV)

Simon Merrells on horseback as Gundleus in The Winter King.

Gundleus (Simon Merrells) is a formidable rival ruler in The Winter King. (Image credit: ITV)

Andrew Gower holding a bowl as Sansum in The Winter King.

Sansum (Andrew Gower) is a fanatical novice in The Winter King. (Image credit: ITV)

Is there a trailer?

Yes, the exciting teaser sees Arthur being banished by his father Uther as Britain is beset by turmoil. Amid fears that "Darkness is coming", Arthur is seen holding his sword, Excalibur, and saying, "It is easy to divide a country, the hard task is putting it back together." He is told, "Only you can save the isle." But as battles and romance come his way, can he win through?

Caren Clark

Caren has been a journalist specializing in TV for almost two decades and is a Senior Features Writer for TV Times, TV & Satellite Week and What’s On TV magazines and she also writes for What to Watch.

Over the years, she has spent many a day in a muddy field or an on-set catering bus chatting to numerous stars on location including the likes of Olivia Colman, David Tennant, Suranne Jones, Jamie Dornan, Dame Judi Dench and Sir Derek Jacobi as well as Hollywood actors such as Glenn Close and Kiefer Sutherland.

Caren will happily sit down and watch any kind of telly (well, maybe not sci-fi!), but she particularly loves period dramas like Call the Midwife, Downton Abbey and The Crown and she’s also a big fan of juicy crime thrillers from Line of Duty to Poirot.

In her spare time, Caren enjoys going to the cinema and theatre or curling up with a good book.