Gillian Anderson will play Margaret Thatcher in 'The Crown' Season 4

The third season of Netflix's royal drama The Crown isn't even out yet, but one crucial role for the show's fourth season has already been cast, and it's a big one.

Deadline reports that Gillian Anderson of The X-Files fame will play the UK's first female prime minister, Margaret Thatcher. The show's Twitter page confirmed the news nine months later with a tweet featuring a quote from Anderson.

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"I am so excited to be joining the cast and crew of The Crown and to have the opportunity to portray such a complicated and controversial woman," the statement reads. "Thatcher was undoubtedly formidable but I am relishing exploring beneath the surface and, dare I say, falling in love with the ice who, whither loved or despised, defined an era."

Thatcher has been portrayed onscreen by nearly a dozen different actors in various productions, most memorably by Meryl Streep in 2011's The Iron Lady. Anderson previously starred in Netflix's original show Sex Education, which was considered a hit for the streaming giant.

Since there's still an entire season worth of stories before Anderson's Thatcher will appear, it's difficult to predict which parts of her career will be covered by Season 4 of The Crown. Going by the pace of the series so far, the fourth season will likely get into the 1970s, and Thatcher was elected Prime Minister in 1979.

At the time of her election, however, Thatcher had served in parliament since 1959 and was Education Secretary from 1970 to 1975; she also served as Leader of the Opposition from 1975 until her election to the Premiership.

So really, it's a toss up. Anderson could play MP Thatcher, Education Secretary Thatcher, Shadow Cabinet Thatcher, Prime Minister Thatcher, or show the progress of her character through the political ranks of the U.K. No one will know anything until at least 2020. Cheers.

UPDATE: Sept. 7, 2019, 5:30 p.m. EDT Story updated with confirmation from the show itself that Anderson had been cast as Thatcher.