Steffan Hill / HBO

The tales of Dunk and Egg are underway. Production on the “Game of Thrones” spinoff series “A Knight of the Seven Kingdoms” has started in Belfast, Ireland. Five actors are joining the cast, including Finn Bennett (“True Detective: Night Country”), Bertie Carvel (“The Crown”), Tanzyn Crawford (“Tiny Beautiful Things”), Daniel Ings (“Sex Education”) and Sam Spruell (“Fargo”).

Sarah Adina Smith (“Lessons In Chemistry,” “Hanna”) will direct three of the six episodes for Season 1; executive producer Owen Harris will direct the other three episodes.

Adapted from George R. R. Martin’s novella “The Hedge Knight,” the first season of “A Knight of the Seven Kingdoms” will follow the exploits of the knight Ser Duncan the Tall (Peter Claffey) and his young squire, Egg (Dexter Sol Ansell), roughly 100 years before the events of “Game of Thrones” and 100 years after the events of “House of the Dragon.” Their journey will take them to a competition in which they encounter several members of the Targaryen dynasty — including Prince Aerion Targaryen (Bennett), Prince Baelor Targaryen (Carvel) and Prince Maekar Targaryen (Spruell) — along with another knight known as the Laughing Storm, Ser Lyonel Baratheon (Ings) and a puppeteer named Tanselle (Crawford).

Clockwise from left: Finn Bennett, Bertie Carvel, Tanzyn Crawford, Sarah Adina Smith, Sam Spruell and Daniel IngsJoseph Sinclair; Handout; Jonny Marlow; Todd Williamson / January Images; Courtesy Pip (2)

The series is written and executive produced by Martin and Ira Parker (“The Sympathizer,” “House of the Dragon”). Ryan Condal, Vince Gerardis, Owen Harris and Sarah Bradshaw are executive producing.

The full logline for the series is: “A century before the events of ‘Game 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.”

Bennett is represented by Tavistock Wood, Public Eye Communications and CAA. Carvel is represented by Hamilton Hodell and Tapestry. Crawford is represented by Zero Gravity Management, Buchwald and MCSM. Ings is represented by United Agents, ColorCreative and CLD Communications. Spruell is represented by Lou Coulson Associates, Luber Roklin and Narrative. Adina Smith is represented by WME Management and 2AM.