At 81, French New Wave auteurEric Rohmer still has the lean, spare frame of his younger days, slightly stooped perhaps, but nonetheless in perfect working order. In this age of profligacy, everything about him and the office of his production company in the heart of Paris suggests temperance. There are no signs of ostentation; even the desk that separates us is devoid of any personal artefacts. He is dressed plainly in slacks and a V-neck sweater. Eric Rohmer has never liked anything to detract from his work, particularly his private life. He has been married for more than 40 years, but that side of his life has been kept from the public eye. This is a director, though, who has made some of the most emotionally inquisitive movies ever made.

Films such as My Night with Maud, Claire's Knee, Pauline at the Beach, Autumn Tale and now his latest The Lady and the Duke have all spun an intricate web of human joys and dilemma without ever falling prey to false sentiment. Rohmer was and remains the most literary of filmmakers, one whose primary concern is less with dealing in what people do than with what is going through their minds as they are doing it.

For many Rohmer's name is inextricably linked with that of the French film review Cahiers du cinéma, which celebrates its fiftieth anniversary this year. He joined the staff of film critic André Bazin's magazine at the outset and in 1956 assumed its editorial control, a position he would hold for the following seven years, working alongside Jean-Luc Godard, François Truffaut, Jacques Rivette and Claude Chabrol. As reviewers they would come to redefine film criticism as an art form. They wrote mainly about films and directors they admired rather than panning those they did not. Rohmer became a staunch supporter of films from directors like Alfred Hitchcock, Roberto Rossellini and F.W. Murnau, men whose work was widely considered unworthy of greatness at that time.

This benign approach to film criticism would eventually foster the kind of co-operative spirit essential to the progression of la nouvelle vague. It was not, though, until 1969, several years after successful efforts by his film-making acolytes, that Rohmer himself completed his first feature-length film, My Night with Maud. The film may have been a long time coming, but its immediate success came as no surprise. Particularly to Truffaut, who told the French magazine Télérama in 1971: 'Between us, I would like to say a little something about the Cahiers du cinéma bunch. We've known for 20 years now, ever since his first films in 16mm, that Rohmer was our master, but he remained an éminence grise.'

Highly appropriate then that the organisers of this month's Venice Film Festival are seeing fit to award Rohmer a Golden Lion for the ensemble of his career. What is surprising is that the notoriously hermit-like director has agreed to accept the award in person. Of course there are certain conditions: that the prize be handed out on 7 September, the final evening of the festival, and that The Lady and the Duke should premier on the same day. As is to be expected, the Venice Mostra declined to kick up any fuss.

But do not expect a belated flurry of public appearances from Rohmer, who is adamant that this is merely the exception that proves the rule. He already declined, he tells me, an invitation to the Cannes film festival earlier this year even though his new film was completed in time for competition. Piqued, Cannes did not screen The Lady and the Duke. When asked why he opted for Venice over Cannes, he guilelessly replies: 'It is simply because Venice has treated me very well.' As for Cannes, there appears to be little love lost between the media-friendly event and the publicity-shy director. And it was at Venice that Rohmer won a Golden Lion for best film in 1986 for The Green Ray. (Curiously, the same movie had a negligible impact in France where it did not even receive a nationwide release.)

Rohmer's deeply held conservative and Catholic values have not always endeared him to the French, particularly his film-making contemporaries. By the Sixties, Cahiers du cinéma had become radically politicised. Rohmer and the more conservative Truffaut were allegedly antagonised by their colleagues on the journal, among their number probably the greatest exponent of New Wave radical cinema Jean-Luc Godard. Jim Hillier's anthology Cahiers du Cinéma has Rohmer accusing his colleagues on the review of a kind of 'terrorism' designed to force him (and Truffaut) to embrace ideas of radical modernism and leftism. In response, Rohmer is quoted as saying that one should not 'be afraid of not being modern... you have to know how to go against the trend of the times'.

This attitude led to to his films finding more favour outside of France. 'In the beginning,' he says, 'the public that sustained my career the most was not so much the French but the Americans, My Night At Maud's [the US title] was a big success there. Now I have quite a lot of success in Europe particularly in Italy, Spain and Germany as well as in Japan.'

Rohmer received a 1969 Academy Award nomination for best original screenplay and best foreign film. My Night with Maud in some ways can be seen as a blueprint for Rohmer's later films, effectively bucking that era's prevailing air of rebellion with a low-key portrait of a man wrestling to equate his Catholicism with his love for a woman who does not believe what he believes. Success was a long time coming for Rohmer, who made his first 16mm short film, Diary of a Scoundrel, back in 1950.

Since then he has made more than 30 films, both short and long, all of them fine examples of his gift for meticulous plotting and tight scripting. Take The Green Ray, a movie as perceptive as Maud , though on this occasion told from a young woman's perspective. Again it focuses on the difficulties and rewards of having courage in one's own convictions. Possibly Rohmer's most lasting cinematic innovation (one that has since been employed by the late Krzysztof Kieslowski in his Dekalog and Three Colours: Red, White, Blue trilogy) is the theme-linked series of films. Sixteen of Rohmer's movies in total belong to such series, including the most recent quartet of films collectively entitled: Tales of the Four Seasons.

In 1971, Rohmer described his motivation for an earlier series of six films, the much cherished Moral Tales: 'I thought audiences and producers would be more likely to accept my idea in this form than in another. Instead of asking myself what subjects were most likely to appeal to audiences. I persuaded myself that the best thing would be to treat the same subject six times over. In the hope that by the sixth time the audience would come to me.'

Rohmer's latest film, The Lady and the Duke, is set during the French Revolution and is based on the memoirs of a Scottish lady, Grace Elliot, a courtesan to the royal courts of both England and France. The story revolves around Elliot's fateful decision to rest in Paris at the outbreak of the Revolution. It is Rohmer's third historical film (the others being 1976's The Marquise of O and 1978's Perceval) and quite unlike anything he has made before.

As always Rohmer spins a well-wrought tale, but what is striking, and quite unlike him, is that in this instance the style of the film is as important as its substance. Rohmer spent three years working with French artist Jean-Baptist Marot to reproduce realistic period Parisian backdrops on dozens of painted tableaux. 'I wanted to show Paris in a light that it has never been seen before in the cinema,' says Rohmer. 'Even in Griffiths's Orphans of the Storm we just see a few bits of street corners, likewise in Abel Gance's Napoleon. So this is the first time we see a film set during the Revolution that really shows what Paris looked like back then.'

With the tableaux completed, Rohmer then set about making his film. First he used digital video cameras to shoot his actors against a plain background. Then using a technique he describes as being 'as old as cinema itself' he had the images encrusted into the already existing paintings. The effect is best illustrated by the stunning opening sequence in which a cityscape comes to life, rather like a pop-up book. Even Rohmer - who is modest to a fault - admits that he was happy with that one.

Typical of Rohmer is that he has chosen to make a costume drama at a time when French cinema is moving in other directions - away from historical films and towards more contemporary genres, a tactic that has revitalised home-grown French cinema. This year for the first time in about a decade Gallic films have outperformed American films at the box office by more than 50 per cent. Rohmer, an advocate of cultural exception, is delighted by this development. 'I think that high art reposes on popular art, without one there cannot be another. Taking this into account I would prefer that there is a French sub-culture in France as opposed to an American one,' he says. 'Even if I admire American cinema enormously I think that each nation should guard its cultural hegemony, otherwise things could become dangerous.'

Rohmer points to Italy and Germany where local distributors have flooded the market with American movies to the detriment of indigenous filmmakers. Of Britain he says: 'There are from time to time some auteurs but most of them end up in the States.'

Rohmer believes that one reason the French film industry is thriving is that there is substantial financial support from the state for native filmmakers. This is something he himself admits to having seen very little of for his films, though he professes not to know why. But he is also quick to stress that this only ensures his own independence.

'I don't owe my success to state subsidies but to a faithful public which has sustained me,' he says. 'Though not huge it has kept me going because my films are not very expensive to make.' His example has influenced filmmakers everywhere, from his countryman Bertrand Tavernier to Hong Kong's rising star Wong-Kar Wai. For not only has Rohmer managed to remain true to himself throughout his career, he has done it in one of the most cut-throat businesses of them all.

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