Of all the adjectives that have been attached to Diana Rigg during her career, 'daunting' comes very high up on the list. To look at her press-cuttings is to see it leaping out at you time and time again, penned by shellshocked journalists who have stumbled dazed and bruised from her presence.
All of which ensures that I am even more nervous than usual when I knock on Rigg's dressing-room door at the Theatre Royal in Norwich where she is appearing in Tennessee Williams' Suddenly Last Summer prior to its West End run.
'Come!' booms a voice from within.
She is a large women - height not width - and in stupendous shape at 65; neither nipped nor tucked, but simply weathering well. This comes as a relief after seeing her tottering round the stage with a walking stick the night before, wearing a snowy white wig. Now, though, the wig is sitting on a polystyrene head in the corner and Rigg is puffing briskly away at a Marlboro Light as rain lashes against the dressing- room window.
'You poor man,' she says, I assume in anticipation of the duffing-up to follow. But there's a smile tugging at the corners of her mouth, along with what might be a twinkle in her eyes. 'So what's your angle then?' she asks. 'I don't really think I have one,' I reply. 'No, I don't suppose you do, because you're a guy. Generally speaking, they don't pitch up with one. And so much the better as far as I'm concerned.' Maybe I've just caught her in a good mood, or maybe she's simply relieved that I'm not a woman - not long ago she had a big dust-up with a female interviewer from the Daily Mail who misquoted her - but at first glance there's nothing remotely daunting about Diana Rigg. If anything, she's rather shy, with a slightly bustery, maternal manner. She's also terrific company: funny, clever and down-to-earth.
'Not long ago, I happened to look at some photographs of myself when I was young,' she says. 'These old, yellowing photographs. And I thought, "Yup, I was pretty beautiful then." I was a corker. But I had no idea, none at all. I pushed it away, because of my upbringing, you see.'
Rigg's early years were spent in Jodhpur in northern India where her father was manager of the state railway. But, aged seven, she was sent to a Quaker boarding school in Buckinghamshire - on her own, not knowing anyone in England and with a luggage label tied to her coat to identify her.
When I suggest that this must have been pretty grim, Rigg gives a shrug and says, 'In a way, but I knew my parents loved me and they didn't have any choice. India was in turmoil at the time and very dangerous. I never felt any sense of rejection. I simply understood it and got on with life.' During the school holidays Rigg was sent to stay with her grandmother in Yorkshire. Once her grandmother caught her looking at herself in the mirror and rebuked her with the words, 'Vanity, vanity.'
'She was a tough old boot. But then, girls weren't encouraged to feel pretty in those days. They were told to keep their place and speak when spoken to.' But you bucked that? 'I did, slightly, yes.'
She certainly chose a vain profession, although Rigg points out that male actors are invariably more vain than female ones, often to be found gazing adoringly at themselves in the mirror. At 17 she went to Rada, followed by a spell at the RSC. And then, in 1965, came The Avengers. Rigg had never seen any of the earlier shows because she didn't own a television and was wholly unprepared for what followed. As Emma Peel, Rigg was half sex-kitten and half-governess - a combination that had an electrifying effect on British men, catapulting her straight to the top of their fantasy wish-list.
For someone who'd never much cared for the way she looked it must have been strange to be turned into this colossal pin-up. 'Oh, it was. But I think I was too level-headed to let it affect me much. I never promoted myself as a sex symbol, but I was definitely photographed as one. And of course I used my sex when necessary. But I just saw it as a layer that someone put on me. To begin with I enjoyed being famous, although not when it impinged on my private life. You know, when you go to an art gallery you want to look at the pictures. You don't want to be conscious that everyone is looking at you. That made me uncomfortable.'
So, too, did the fact that she was given no guidance on how to cope with all the attention. 'Hundreds of letters suddenly came in, all asking for signed photographs. I wasn't earning enough to employ a secretary and I didn't have any photos of myself, so I didn't know what to do. I used to drive around with these bags of letters in the back of my Mini. Then, when my dad died, my mum became my secretary and she got very good at forging my signature. There are photos of me all round the world with my mum's signature on them.'
But while Rigg may have found fame tricky to handle, anyone treating her as soft touch soon learnt that Emma Peel's famously disabling karate kicks weren't confined to the screen. On The Avengers she discovered she was being paid less than the cameraman and kicked up a stink. As a result her salary doubled from £90 a week to £180.
None the less, after just two series she decided she'd had enough. 'I wanted to do other things - that was all.' She got bored? Rigg nods. 'I've always been a bit perverse like that. Most people like going into a play and staying there, but I like moving on. It is boredom, I suppose. I even bore myself on stage sometimes. I'll be in the middle of a speech and think, "Oh, do shut up."'
This is accompanied by a throaty chuckle. One of Rigg's greatest assets as an actress is her voice: rich, breathy and incorrigibly posh. The combination of this and her 'corker' looks ensured that Hollywood soon came calling. In 1969 Rigg starred opposite George Lazenby in On Her Majesty's Secret Service. According to press reports, they made a far from harmonious pairing. Rigg, however, insists she loved every minute of it.
'I'd never done a mega-mega movie before. It was everything I hoped it would be. The champagne would be opened at midday and everyone was at it like rabbits. Telly Savalas was shovelling girlies in and out the whole time and George Lazenby was a very busy boy, too. Then, afterwards, there was a sort of ruckus because Lazenby decided to shoot his mouth off and say that I'd purposely eaten garlic before I shot a love scene with him. I denied it, of course, because it wasn't true.' There is a pause, then Rigg half raises an eyebrow and says in a devastatingly offhand way, 'I don't know what's happened to him now.'
By her own admission, Rigg was 'quite naughty' in the 1960s. Her first marriage - to an Israeli painter called Menachem Gueffen - only lasted a couple of years. Then in 1977 she had a daughter, Rachael, by the Scottish landowner, Archie Stirling, whom she married five years later. Rachael is now a well-known actress: she starred in last year's television adaptation of Sarah Waters's novel, Tipping the Velvet.
'Having a baby was quite a conscious decision because I had met "the Father",' Rigg says. 'I think that's often a big factor in a woman's decision - suitability of father - and Arch did indeed prove to be a wonderful parent.' This is more information than Rigg normally gives on the subject of marriage - she has never spoken publicly about either husband - but that's as far as she's prepared to go. In the 1980s she spent much of her time shuttling back and forth between London and Scotland, concentrating more on motherhood and less on acting. 'Acting did become less important. And I've never quite clambered out of that. I'd be sad if I couldn't act again, but it wouldn't be a disaster. At the same time I do love it. The sense of exhilaration when you get something right is wonderful.'
Her marriage to Stirling fell apart in 1990 after he had an affair with the actress Joely Richardson. Soon afterwards came Rigg's Indian summer as an actress. Starring roles in stage productions of Medea, Mother Courage, Who's Afraid of Virginia Woolf? and Phedre won Rigg ecstatic reviews, a clutch of awards and even enoblement - she was made a dame in 1994.
Various critics have suggested that personal suffering broadened her range as an actress, but Rigg thinks this is rubbish. 'This whole question makes me slightly irritated. I think that with maturity comes a great deal. You gain knowledge of the human condition and the ability to play certain aspects of it which are alien to you. Mother Courage? I had very little in common with that woman, yet I think I did a good job. Medea? No. Phedre? No. It rather minimises our art if the belief is widely held that you can't play something until you've experienced it.'
But while Rigg is adamant that acting should be taken seriously, she doesn't take herself very seriously at all. When she appeared in Humble Boy at the National Theatre in 2001, her entry in the programme - in marked contrast to everyone else's exhaustive credits - read, 'Diana Rigg has been around for a very long time and this is the sixth time she has coupled with Denis Quilley'.
Rigg is now happily single and insists she's perfectly content with her lot. Not only is she a dame, but also chancellor of Stirling University and chairman of the MacRoberts Artes Centre. 'I love being treated with gravitas and I hope a little of it rubs off on me.' When she's not working, she spends much og her time in her chateau in France. Is it a very big chateau? 'Huge!' says Rigg, delightedly. 'I love it there. Being on my own doesn't bother me but, in fact, I lead a very social life in France. They don't let you be alone.'
Rigg's Avengers co-star, Patrick Macnee once said of her, 'Diana is the sweetest, most confrontational person I know.' Certainly, she's not one to back down from a fight. In 2001, when an article in the Daily Mail suggested that she had a low regard for British men and that she had retired to become a recluse in France, she sued and won almost £40,000. Similarly, during the run of Humble Boy at the National Theatre, she didn't hide her displeasure at the dressing-room facilities, describing them as 'battery-hen hatches'.
When I put Macnee's quote to her, Rigg looks shocked. 'Patrick said that? But I don't think I'm confrontational. In fact, I don't like confrontations - not at all. I'm all for manners. I think they're terribly important. Manners, loyalty, honesty. These are things I believe in. But then, you see, I am terribly old-fashioned.'