Diana Rigg once 'stormed off' the set of Game of Thrones – and inspired costars

The great, late Diana Rigg was an inspiring and intimidating force both on and off camera as the Queen of Thorns Olenna Tyrell.

As detailed in the upcoming book Fire Cannot Kill a Dragon – the first uncensored behind-the-scenes story of making Game of Thrones – Rigg was not only formidable as the crafty House Tyrell matriarch across five seasons of the HBO fantasy series, she could be fierce backstage as well.

The Royal Shakespeare Company veteran, who died earlier this month, was 74 when she was offered a recurring role in the series by showrunners David Benioff and Dan Weiss in 2012. "We had tea with her," Benioff recalls. "Dames don't audition for you; you audition for them. We loved her, she was funny, she was bawdy, she was everything we wanted for that character." Adds Weiss: "She said with a big smile, 'There's an awful lot of bonking, isn't there?'" of the show's R-rated content.

Then Rigg impressed the producers by arriving at her first table read having already memorized all her lines for the season, showing some of the less experienced cast members how a seasoned pro prepares for a job.

Over the years, Rigg continually stunned with her ability to deliver instant-classic takes on the writers' material and helped make many lines iconic, such as: "I’ve known a great many clever men. I’ve outlived them all. You know why? I ignored them," and "I wonder if you’re the worst person I’ve ever met. At a certain age, it’s hard to recall, but the truly vile do stand out through the years."

Related: Killed-off characters on "Game of Thrones" Season 7 (2017)

But Rigg also had a clear mind as to how her scenes should be performed and wasn't always amenable to suggestions. "I was terrified of Diana Rigg," says Emmy-nominated director Mark Mylod, a sentiment echoed by other directors during interviews conducted for the book last year. "My very first scene with her, I asked her to do a very minor thing. Like, 'Would it make sense if you close the door and walk a few paces before this moment?' She came back with some rebuttal about why she wanted to do it another way and then said: 'Thank you! Go away!' I became a five-year-old boy. I could feel myself blushing and creeping back to my monitor, stripped of any kind of dignity or authority."

Yet Rigg's high level of skill – she earned four Emmy nominations playing Olenna – was invaluable for those fortunate enough to perform opposite her, such as Rigg's frequent scene partner Natalie Dormer, who played Olenna's ambitious granddaughter Margaery Tyrell. "When you have someone who has that many accolades, you just shut up and watch," Dormer says. "She had a very dry sense of humor and was aware of the parody of herself. Sometimes I think she was mischievous to see what she could get away with."

One time Rigg tried – and succeeded – in mischievously getting away with shortening her duties to perform a brief scene in season six. It was the scene where Olenna discusses strategy with Ellaria Sand and famously cuts short Sand Snakes Obara, Nymeria and Tyene by snapping, "Oh do shut up ... Let the grown women speak."

"She walked onto the set, and she went, 'I’m ready now!'" recalls Jessica Henwick, who played the whip-snapping Nymeria Sand. "A cameraman came over and went, 'Well, okay, but we haven’t finished setting up.' She interrupted him and said, 'Roll the cameras!' And she just started doing her lines. She did two takes, and then the guy came over and was like, 'Great, now we’re going to do a close-up.' And she just stood up and she went, 'I’m done!'"

"Now, she can’t walk fast. She has to be helped. So basically we just sat there and watched as Diana Rigg effectively did her own version of storming off the set, but it was at 0.1 miles per hour. She cracked me up. I loved her."

Rigg also had a one-on-one scene with Emilia Clarke. Like other actors on the show, Clarke recalled being in awe of the dame's abilities and just trying to remain present as her character. "I only had one scene with her and was very blessed to have had that," the Daenerys Targaryen actress says. "Like with Peter [Dinklage], it was watching an acting master class. I kept thinking: “Okay, not my line yet, I’m not just watching you — really! I’m acting with you. . . .”

In that scene, Olenna gave Daenerys her most famous pieces of advice: "The lords of Westeros are sheep. Are you a sheep? No. You’re a dragon. Be a dragon."

Benioff and Weiss expanded Olenna's role from author George R.R. Martin's novels to double down on Rigg's strength as a performer. But Olenna's arc ended in season 7 in one of the show's finest death scenes. The Queen of Thorns turned the tables on a stunned Jaime Lannister after the Kingslayer ordered her to drink fatal poison by confessing she masterminded the murder of Joffrey Baratheon – “Tell Cersei. I want her to know it was me."

Says Weiss: “Olenna was probably the only character to win her own death scene."

For the full inside account of making Thrones, Fire Cannot Kill a Dragon is coming Oct. 6 and available for preorder now.

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