“All I ever wanted to do was play Shakespeare, nothing else. It was a kind of zenith for me,” says Judi Dench, discussing her first professional role (Ophelia with the Old Vic) straight out of drama school in 1957. Despite the book’s jokily disparaging subtitle – “the man who pays the rent” is how Dench and her late husband,Michael Williams, used to refer to the Bard when they both worked for the Royal Shakespeare Company during the 1970s – her passion for Shakespeare shines through every conversation reproduced here.

The book is the result of four years of interviews with Dench by the actor and director Brendan O’Hea, who has known her for 30 years, and were originally intended as recordings for the archive at the Globe theatre, where he is an associate artist. Transcripts can run the risk of feeling somewhat dead on the page, but Shakespeare is saved from that fate, partly by skilful editing, so that the teasing, sparring and mischief that characterised Dench’s side of the conversation is faithfully reproduced here, with O’Hea as her straight man, but largely because her voice is so distinctive and familiar that you can hear it in your head. When she talks about Shakespeare’s characters, it is as if she is discussing the flaws and preoccupations of people she knows intimately. A further personal touch is provided by Dench’s own watercolour sketches of characters, which she was persuaded to include on the grounds that they might encourage others who, like her, are visually impaired, to paint.

Over the course of her seven-decade career, Dench, now 88, has played most of Shakespeare’s major female roles on stage, from her 1957 Ophelia to her 2015 stage run as Paulina in The Winter’s Tale at the age of 81, in addition to memorable performances for film and radio. The book is organised around each of these characters, with O’Hea’s questions prompting an examination of motive and intention, and Dench’s replies often digressing into anecdotes about particular performances and the other actors and directors involved. From this perspective, you can see why the interviews were conceived as an archive resource; with her longevity and extraordinarily sharp memory, Dench is a one-woman repository of British postwar theatre history. She recounts her experiences of working with well-known directors of Shakespeare – Peter Brook, John Barton, Peter Hall, Terry Hands, Trevor Nunn, Kenneth Branagh – and playing opposite some of the greatest actors, including Ralph Richardson, John Gielgud, Coral Browne, Peggy Ashcroft and, of course, “Mikey”, with whom she often worked, especially in the early years of their marriage, though she says they never talked shop at home: “It wasn’t a conscious decision; it was just the way it fell out. I think it’s good to keep the lid on things. Overshare, and you let the air in.”

The chapters on individual plays are interspersed with sections on broader aspects of performance, under headings such as Company, Rehearsal, Critics, Audience and the delightfully general Fireside Ramblings. What comes across most forcefully from these sections, apart from Dench’s impish humour, is her conception of any production as an ensemble effort and not as the vehicle for a star. “You very rarely talk about yourself in isolation,” O’Hea observes at one point. “It’s only ever in relation to the other actors or the audience.” Dench regards this as obvious: “Of course – otherwise you’re acting in a vacuum … Acting is a three-way conversation between you, the other actors and the audience.” She’s quick to shut down any attempts on her interviewer’s part to overintellectualise either the plays or her “process”; when O’Hea explains that “nothing” is thought to be Elizabethan slang for female genitalia, she retorts: “Much Ado About Vagina? Don’t be ridiculous … Some dirty-minded scholar with no sex life has made that up.”

Her process is revealed to be both instinctive and pragmatic, erring on the side of “less is more”, an approach she “learned from standing in the wings at the Vic every night and watching what was happening on stage”. She laments the demise of the repertory system in this regard, but believes passionately in the importance of keeping the plays alive: “Shakespeare is an international language, a beacon for humanity, and a bridge across cultures.”

Lest that sound too high-minded, be assured that the book is full of ribald anecdotes, many involving, in true Shakespearean style, mistaken identities. She tells of one promenade production where she spotted a director she knew in the audience and dropped a note into his lap as she passed that read “I suppose a fuck’s out of the question”. “But when I glanced over during the scene, I saw that it wasn’t Howard at all, but a much older gentleman who looked very alarmed.”

This is a gloriously entertaining tour through the canon in the company of perhaps the most experienced living Shakespearean actor; reading it feels like a chat with an old friend.

• Shakespeare: The Man Who Pays the Rent by Judi Dench (with Brendan O’Hea) is published by Michael Joseph in the UK (£25) and Penguin Books in Australia ($36.99) on 8 November. To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply