There ’s a novel man in Westeros and once again a crowd of Targaryens .

Fresh offHouse of the Dragonpremiering its second season on Sunday, HBO has announced that anotherGame of Thronesprequel is officially in production.

On Tuesday, the network revealed that work onA Knight of the Seven Kingdomsis underway in Belfast, Northern Ireland. Better yet, they also released a first photo:

The image depicts actor Peter Claffey as Ser Duncan the Tall. A former rugby player, you might know Peter from the British seriesWreckor an appearance on the Irish seriesBad Sisters. He’s also in Season 3 ofVikings: Valhalla,which premieres in July.

His and child actorDexterSol Ansell’s castings were previously announced in April. According toEntertainment Weekly, Dexter plays “Egg,” Duncan’s squire. Dexter played Young Coriolanus inThe Hunger Games: The Ballad of Songbirds & Snakes.

Peter and Dexter are the stars ofA Knight of the Seven Kingdoms, which is based onGame of Thronesauthor George R. R. Martin’s 1998 novellaThe Hedge Knight.

Here’s the new series' logline, courtesy of HBO: “A century before the events ofGame of Thrones, two unlikely heroes wandered Westeros…a young, naïve but courageous knight, Ser Duncan the Tall, and his diminutive squire, Egg. Set in an age when the Targaryen line still holds the Iron Throne, and the memory of the last dragon has not yet passed from living memory, great destinies, powerful foes, and dangerous exploits all await these improbable and incomparable friends.”

The network also announced on Tuesday that several other actors have been cast in major roles in the series, includingTrue Detective: Night Countrystar Finn Bennett as Aerion Targaryen.

Bertie Carvel, who played UK Prime Minister Tony Blair onThe Crown, has been cast as Baelor Targaryen.

Tanzyn Crawford, of the Hulu miniseriesTiny Beautiful Things, will play Tanselle.

Daniel Ings, who starred in the recent Netflix seriesThe Gentlemen, will play Ser Lyonel Baratheon.

Finally, Sam Spruell, who appeared in Season 5 ofFargo, is Maekar Targaryen.

No word just yet on whenA Knight of the Seven Kingdomswill air. Luckily, withHouse of the Dragonjust beginning Season 2, that should hopefully tide overGoTfans for some time.

Emma D'Arcy as Rhaenyra Targaryen wears a dark medieval-style outfit, standing on a rocky seaside landscape, from the TV show "House of the Dragon."

A man is seen walking through a village in a scene from "A Knight of the Seven Kingdoms"

Closeup of Peter Claffey at a media event

Closeup of Dexter Sol Ansell smiling on the red carpet wearing a vest, a patterned blazer, and jeans

George R.R. Martin on the "House of the Dragon" red carpet, wearing a paisley vest, a dark shirt, striped pants, and a cap

Closeup of Finn Bennett

Closeup of Bertie Carvel

Closeup of Tanzyn Crawford

Closeup of Daniel Ings

Closeup of Sam Spruell