The actress, 68, received critical acclaim for her portrayal of the late Queen in the final two seasons of The Crown.
The star likened the responsibility the Queen must have felt on becoming the monarch to how a woman might feel joining a convent.
Speaking to British Vogue, she said: ‘What I admire,'[is how she] was the last bastion of, ”I’ve said I would do this”.
‘That’s over now, that’s gone. Someone who would turn up, come rain or come shine – people don’t do that in any walk of life now.
‘I do believe that being anointed Queen was [for her] like becoming a nun, the degree of responsibility she felt was enormous.’
The star has previously admitted to struggling to shake off her Netflix drama character, which she played for two series, as she continued to wear a number of outfits from the show.
During an event earlier this month, she said: ‘It was quite a serious job and quite a serious responsibility carrying all that stuff.
‘I finished doing that last May and June and shaking that off — so now I can be up and funny — it’s just taken me that time.
‘I was doing it day in, day out. I knew in 2019 I was doing it, and I started in 2021, so it was a long time. Four years of her in my head.
‘The work that went in, you can see it on the screen, every detail from the set to the costumes. I’m wearing one of her shirts now.’
Elsewhere during her British Vogue interview, Imelda revealed that she makes her marriage to her husband Jim Carter work by ‘taking life more seriously than her job.’
Imelda has been married to the Downton Abbey actor, 75, since 1983, and in a new interview shared that even during their busy schedules, they’ve always made time to visit each other when filming abroad.
The actress shared that she and Jim have ‘worked’ to ensure they can find time together away from their various acting roles.
She added that one such challenge came during her acclaimed eight-month run as Mumma Rose in Gypsy in 2015, which she described as ‘tough’ on Jim.
Imelda explained: ‘Success means working, Success is a really tricky word, and it should be spelled with a very small S.
‘I think it poisons people. I feel Jim [Carter, her husband] and I have made our lives work as a marriage within this business, and we take our life more seriously than our jobs.
‘Of course, we both take [the job] very seriously. But you go, what’s the most important thing here? That I play another part?
‘Or that we go on a very nice holiday, or that we have that time in the garden, that we have our life?
‘But we can afford to say that – I don’t mean financially, but with the work we’ve done and are lucky enough to still be doing. I think we know how fortunate we are.’
Imelda continued: ‘I think when we got married, we did say, look, there’s no point if we’re going to be apart.
‘Early on, Jim did a lot more telly and films than I was doing in the ’80s. If he was going to go to an exotic location, we’d go, ”Right, well, I can come out that weekend.” So we made that work. Or there’s two jobs, ”I can go and do that. Do you need to do that? OK? Lovely.”
Reflecting on her Oliver Award-winning turn in Gypsy, Imelda added that her lengthy run in the show was ‘tough’ on Jim.
She added: ‘I don’t see anyone, I don’t do anything. I don’t socialise. I don’t do anything. And that’s fine because my job is to do this. I would be so embarrassed if I couldn’t do my job because I had some drinks.’
The actress is set to return to the theatre in a producton of Hello Dolly! at the London Palladium, and she told Vogue: ‘What I quite like is that, yes, her name is Dolly Levi, but she was born Dolly Gallagher.
‘And so you’ve got the gift of the gab, you’ve got the wheeling and the dealing and a woman who’s been left to fend for herself financially and emotionally.’
It comes after Imelda confirmed there will be a third and ‘final’ Downton Abbey movie, during a tell-all interview with Zoe Ball on Radio 2.
The actress, plays one of Queen Mary’s ladies-in-waiting Lady Maud Bagshaw in the much-loved TV show and movie.
And spilling the tea for the listeners on the radio show, Imelda didn’t hold back to reveal the exclusive news.
Zoe, 53, said: ‘Lots of people are asking me because obviously Jim [Carter] is your chap. Do you know about Downton, and the rumours? There’s more coming. Have we… yes? There is? What do you know? What can you say?’
Without hesitation, Imelda said: ‘Right. There will be… the final… film. There you go.’
Zoe gasped: ‘Wow! That’s it, that’s all she’s got but that’s pretty huge Imelda! Fantastic – I hope we haven’t got you in any trouble at all.’
Imelda grinned: ‘I don’t care!’
Zoe added: ‘You don’t care anyway. You’re wild like that and I love it! You get to that point in life and you’re like “I don’t care anyway”.’
Imelda has starred in the movie with her real-life actor husband Jim Carter – who plays butler Carson.
