Five New Cast Members Added to Untitled Game of Thrones Prequel Pilot

The cast of HBO’s untitled Game of Thrones prequel pilot is beginning to take shape. Five new cast members have come onboard as of Wednesday, including Marquis Rodriguez, John Simm, Richard McCabe, John Heffernan and Dixie Egerickx, per EW.

The series was created by Jane Goldman and George R. R. Martin, and Goldman wrote the script based on a story by her and Martin that takes place thousands of years before the events of Game of Thrones. The series is said to explore the fabled Golden Age of Heroes and how it descended into the Long Night, the original war against the white walkers.

Rodriguez is best known for his roles in Definitely, Maybe, and the Netflix series Luke Cage and Iron Fist. Simm has appeared onscreen in Doctor Who and Life on Mars, and is set to play the title character in an upcoming stage production of Macbeth. McCabe is known for his work with the Royal Shakespeare Company and for his role in the 1999 film Notting Hill. Heffernan has extensive stage experience as well, having performed with various high-profile British acting companies. Egerickx is a 13-year-old actor known for her roles in The Little Stranger and the miniseries Patrick Melrose.

The new cast members will join the previously announced cast of Naomi Watts, Josh Whitehouse, Jamie Campbell Bower, Naomi Ackie, Denise Gough, Sheila Atim, Ivanno Jeremiah, Georgie Henley, Alex Sharp, Toby Regbo and Miranda Richardson. The series will be executive produced by Goldman, Martin, Game of Thrones co-executive producer Vince Gerardis and Bloodline co-creator Daniel Zelman. It will also be co-executive produced by BBC Studios’ James Farrell, Jim Danger Gray of Orange is the New Black, Sarah Lee Hess and Chris Symes.

The production timeline for the new series remains unknown—catch up on everything else we know about the project so far here. The final season of Game of Thrones premieres on HBO April 14.