The British actress has landed a role alongside Naomi Watts, Josh Whitehouse, Naomi Ackie, Denise Gough, and Jamie Campbell Bower in writers Jane Goldman and George R.R. Martin's new project, which is set thousands of years before the events of "Game of Thrones".
Richardson is perhaps best known for her role as Rita Skeeter in the "Harry Potter" franchise. She also appeared in 1999's "Sleepy Hollow" and "The Hours".
Goldman and Martin will executive produce with Vince Gerardis and "Damages" and "Bloodline" co-creator Daniel Zelman, among others and production on the prequel is planned for this summer.