Dame Judi Dench, 80
One of the greatest actresses of her generation, Dame Judi has been nominated for more than 200 awards for stage, screen and film work, including an Oscar win for her role in 'Shakespeare in Love'. She lives in Surrey
He'd known my husband [Michael Williams] from ages ago, as they were both performing in Hamlet in the mid-1960s. But we didn't meet one another until a production of King Lear in the 1970s. He was really good as Edgar, and we got on instantly. He had a wonderful sense of humour, though he didn't behave as badly as I did; in fact, he frequently pulled me back. I was doing tapestry [off stage] the whole time, making rude cushions for people. One said "Fuck 'em" all the way round it!
We didn't really get to know one another until a few years later, when we were cast opposite each other in The Way of the World. I had a glorious time in it, and he had a great role as the lead. That was followed by another play in which we played husband and wife, called The Gift of the Gorgon, in which Michael got another plum role. So after that he was forever known as Mr Plum. Afterwards, I tried to send a plum of some kind for every birthday he had: plum jam, plum trees…
We've played lovers or partners several times. It's easier to play someone's wife or lover when you've known them a long time, as you don't mind making a fool of yourself and you're more relaxed about it.
But The Gift of the Gorgon was a play I never quite cracked, and I was on edge throughout. He put up with me fantastically well. When we came to the last run-through, I was in a white-hot panic and ran to the loo, where I stayed: I just wanted to go home. But Michael was wonderful with me and when I came out, he was a reassuring presence and kept me steady.
He's come to my rescue a lot: When we did the Italian play Filumena together, I had a great list of Italian towns to reel off and I completely dried up, in extreme panic: I could only think of pasta dishes. And I cut an enormous piece of the play out, too. But Michael kept his head, for which I'm eternally grateful, and calmly got us back on track.
When we have argued, I don't think it's ever been serious. I remember him telling me once that he had a mouse infestation and had set mouse traps all over his house. I won't have a trap in my house: I don't like badgers being destroyed or maimed, and I feel the same about mice. So I wrote these anonymous letters to him saying, "Mouse Murderer!"
We've gone on to different things – I've focused more on films – but I feel like I've always known him, and he's always been there, a rock-like friend. But mostly it's been about having fun and being badly behaved. Though he's not as uncontrolled as I can get: once he ate a lot of garlic before a love scene; I think I punched him for that.
Michael Pennington, 71
A stage actor and director, Pennington has played most of the major Shakespeare parts for the RSC and the English Shakespeare Company, which he co-founded. He has also appeared on screen, as commander of the second Death Star in 'Return of the Jedi' and as Michael Foot in 'The Iron Lady'. He lives in north London
Judi is one of the reasons I went into theatre. As a schoolboy I watched her 1957 debut as Ophelia in a Hamlet production in London, and she was elegant without effort. It was her big debut and everyone knew that a potential new champion was leaving the starting blocks.
I didn't see her again for 12 years, when [her husband] Michael, Judi and I were at the RSC in Stratford. It was a big company so the only play I was in with her was King Lear – she played Regan. When not rehearsing, she'd spend the whole time knitting feverishly. I remember asking, what is this knitting? And she told me, "Cardigans for my daughter."
Two years later we did a play together called The Way of the World. It was the first time I was a leading man, and she was the leading lady: there were lots of scenes with rallies of wit and humour between us. You don't half raise your game when you play with someone that good – I learnt a lot.
Time went by and 15 years later we did the Peter Shaffer play The Gift of the Gorgon, again playing husband and wife – and another plum role for me. I said, the thing I like with you is that I get all the plum parts: after that we both insisted on being called Mr and Mrs Plum and gave each other plum-related birthday gifts.
It was not a secret that she didn't like doing that production. She was on edge for a lot of it. I remember once being cheeky with her during a rehearsal and she threw a fruit salad in my face. I pretended I was upset for a day or two and the whole company thought there was a feud. At the final rehearsal, she threw the script down and ran to the loo, refusing to come out, and I sat there, baffled. Her unease didn't make any difference; she was wonderful in it.
We both take acting seriously, but we also know that what we do – putting on a costume and pretending to be someone else – is inherently daft. She can be a terrific tragic actress, but part of the fun with her is that at any moment she's going to burst out laughing.
Since I last worked with her she's become a movie star: a whole generation don't know so much of her from the 1960s and 1970s, but as "M" in the Bond movies. But she's not lost her outrageous sense of a practical joke: about 10 years ago, when she was the countess in All's Well that Ends Well, when she'd finish a scene, she'd dash outside and along to Les Misérables next door, slip on a costume and join the chorus line. There's no one quite like Judi. For her, acting is playing: she's a lass unparalleled.
'Let Me Play the Lion Too: How to be an Actor', by Michael Pennington (£17.99, Faber), is out now. Pennington will be discussing the book at the National Theatre, London SE1 (nationaltheatre.org.uk), on 9 FebruaryReuse content