As fans prepare to say goodbye to HBO's high fantasy drama Game of Thrones when the final season airs in April, production is underway on the currently unnamed prequel series.

Now, five new actors have been added to the cast, according to Variety. For viewers of Marvel's now-canceled series' on Netflix, the most familiar name will be Marquis Rodriquez, who played Darryl in Season 1 of Luke Cage and carried the role into Season 1 of Iron Fist.

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The other actors announced are John Simm, Richard McCabe, John Heffernan and the young Dixie Egerickx.

The show will be set thousands of years before Game of Thrones, portraying events from the prehistory of Westeros. Currently, little has been revealed about characters or the plot, but the new casting announcements join a list of confirmed actors including Naomi Watts, Josh Whitehouse, Georgie Henley, Naomi Ackie, Denise Gough, Jamie Campbell Bower, Toby Regbo, Sheila Atim, Ivanno Jeremiah, Alex Sharp and Miranda Richardson.

The series is expected to begin filming soon. Jane Goldman will serve as writer and showrunner, working with author George R.R. Martin, who wrote the book series which was used as the basis for Game of Thrones.

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Season 8 of Game of Thrones, the show’s final season, will premiere April 14. It will feature six episodes with longer than usual runtimes. The HBO drama stars Peter Dinklage as Tyrion Lannister, Nikolaj Coster-Waldau as Jaime Lannister, Lena Headey as Cersei Lannister, Emilia Clarke as Daenerys Targaryen, Sophie Turner as Sansa Stark, Maisie Williams as Arya Stark and Kit Harington as Jon Snow.