The 'Game of Thrones' prequel has added another strong cast member.

The pilot for the as-yet-untitled 'Game of Thrones' prequel will see Miranda Richardson join the cast in an unspecified role.

If Richardson looks familiar, it's because she's played one of the most annoying characters to ever be given the light of day - Rita Skeeter from 'Harry Potter'. Of course, that's not all Richardson is famous for, having played Queen Elizabeth in 'Blackaddder' and being nominated for two Oscars in 1993 and 1995.

If you've been watching Sean Bean's new Sky series 'Curfew' recently, Richardson plays Lou Collins, opposite Thaddea Graham's Hanmei. She's also lined up to appear in Neil Gaiman’s 'Good Omens' adaptation for Amazon later this year, set to star David Tennant, Benedict Cumberbatch, Michael Sheen, and a host of other big names.

The 'Game of Thrones' prequel series will see Richardson join the likes of Josh Whitehouse, Denise Gough, Jamie Campbell Bower, Sheila Atim, and Toby Regbo who have all been cast in unspecified roles. Naomi Watts, who has been cast in the lead role, has had her character described as "a socialite who hides a dark secret." Filming of the pilot is already expected to be underway in Belfast.

For a pilot show, we actually seem to have been given quite a bit of information on what we can expect. Should it make it to a series, it will explore the origins of the Whitewalkers, and is expected to take place thousands of years before the characters we know and love even existed. HBO have said the series "chronicles the world’s descent from the golden Age of Heroes into its darkest hour."

Just don't expect to see the new prequel series anytime before 2020 at least. Before that of course, we have the final season of 'Game of Thrones' to look forward to.

Via Variety.