She’ll soon be back on our TV screens as the formidable matriarch Olenna Tyrell, whose sharp tongue and taste for intrigue has earned her the nickname “Queen of Thorns”.
“I love playing bad women. They’re so much better to play than the goody two shoes!” declares Dame Diana, who is relishing her role in the sixth series adapted from George R R Martin’s fantasy novels, A Song of Ice and Fire, due to air in late April.
“Game of Thrones has a lot of British actors in it, and we're so grateful for the opportunity!” she jokes. “We just get on with it, we don't ask for a 60 foot Winnebago, we don't have a personal chef or a personal assistant, we don't ask for a specific coffee machine – naming no names!”
Appearing in the popular TV show means adapting to the requirements of a big-budget production.
“I did one scene in Game of Thrones which took 28 takes - just for a two person scene!” she exclaims. “It’s not just down to the director any more, all the producers have to have a say. I told them it works on the law of diminishing returns: I give my best in the first few takes one two and three are good, four five and six are ok, but seven, eight and nine… not so great…”
The multiple takes are a contrast to the immediacy of live theatre, where Dame Diana started out, after studying at RADA then joining the Royal Shakespeare Company.
“My first season at Stratford as a walk-on was with Laurence Olivier in Coriolanus,” she recalls.”Olivier got stabbed on a cliff top and fell over backwards. There were gasps from the audience. It was a great dramatic moment.”
TV stardom beckoned in 1965 when she joined Patrick Mcnee in the Avengers, as Emma Peel, a character famed for her eye-catching outfits, especially the figure-hugging black leather catsuits.
“The series was so popular, all the mail came flooding in, but I was too busy to respond to it so I shunted it all off to my mum, “ she confesses.”She sometimes wrote back and she signed countless photographs…”
She went on to play Countess Teresa di Vicenzo in the 1969 Bond film On Her Majesty’s Secret Service, opposite George Lazenby.
“It was one of the most popular Bond movies, but he misbehaved on and off the set, he screwed up – he had his chance and he blew it,” she says.
While her own career has included many successes, including a BAFTA for the BBC mini series Mother Love, and being made a Dame of the British Empire in 1994, she’s philosophical about the occasional failures that have happened along the way.
“I love the failures - they’re so delicious!” she smiles. “The disasters are wonderful, because you laugh so much. When I was in the musical Colette, we opened in Seattle and closed in Denver!”
One of her few regrets is appearing naked in Abelard and Heloise for her Broadway debut, which lead one ungallant reviewer to describe her as “built like a brick mausoleum with insufficient flying buttresses”.
Undeterred, Diana made the most of theatre’s most memorable disasters by compiling a collection entitled No Turn Unstoned: Worst Ever Theatrical Reviews, unearthing barbed comments dating as far back as ancient Greece.
“The theatre has a fascinating history, it all started with Thespis – in Greek theatre, he was the first to step out of the chorus and play a part - and now actors are known as Thespians,” explains Dame Diana.
“Greek tragedies, like Medea and Phedre, have plots about dysfunctional families, and huge speeches, which make them really difficult to do, but it's a great opportunity because you stretch yourself physically emotionally and intellectually.”
At the age of 77, she’s still keen to rise to those challenges – so will there be more of her in Game of Thrones in future? As the TV series doesn’t strictly follow the plot line of the novels, she’s not ruling it out.
“My character’s been killed off in the books - but in the TV series she hasn’t – not yet!” she smiles.
A Conversation with Dame Diana Rigg was hosted by writer and broadcaster Edward Seckerson at St James Theatre. Next in the series is A Conversation with Anita Dobson at St James Theatre on 20 March 2016.