In 1959, Francois Truffaut was 27 and on top of the world.

The handsome young French filmmaker had just won the director's prize at Cannes for his first feature, "The 400 Blows."

Enjoying the adulation with him was Jean-Pierre Leaud, the 14-year-old sensation who starred in his quasi-autobiographical movie and who would become his perennial alter ego.

Truffaut's film, an unsentimental, fictionalized evocation of his own childhood, set a new standard for first-person storytelling in the movies. This was the age of the director as superstar, as chronicler of modern life, warts and all. The so-called "New Wave" movement had finally arrived on the world stage.

Yet for all its apparent auspiciousness, this moment would be the last unequivocal triumph of Truffaut's career.

Thanks to a month-long retrospective of his work at the National Gallery of Art and the American Film Institute starting this weekend, we can reexperience Truffaut's sometimes exhilarating, often torturous journey between "The 400 Blows" ("Les Quatre Cents Coups") and the 1982 "Confidentially Yours," the final film before he succumbed to a brain tumor.

Like the final, freeze-frame image of "The 400 Blows," in which young Antoine Doinel (played by Leaud) stands hesitantly between the detention center he just escaped from and the forbidding sea ahead, Truffaut would stay forever poised on the edge of promise. He would enjoy success again. But it would always be tempered with disappointment and setback.

There would be more box office failures than hits. There were public battles with his parents over the portrayal of Truffaut's family life in "The 400 Blows." There were blistering attacks from the press, which would accuse him of everything from sleazy careerism (because of his marriage to the daughter of a film producer) to artistic treachery.

Personal success would be even more elusive. His marriage to Madeleine Morgenstern, the daughter of producer-distributor Ignace Morgenstern, ended in 1965 largely because of Truffaut's obsession with sex.

The filmmaker almost routinely slept with his leading ladies, including Catherine Deneuve (who starred in Truffaut's 1969 "Mississippi Mermaid") and Jacqueline Bisset (who appeared in "Day for Night" in 1973) as well as innumerable starlets, strangers and even professionals.

According to Antoine de Baecque and Serge Toubiana's definitive "Truffaut: A Biography," Truffaut frequented prostitutes for most of his life and contracted venereal disease on more than one occasion. He was, like the title of his 1977 film, the man who loved women.

Actress Jeanne Moreau, who starred in Truffaut's seminal 1962 film "Jules and Jim" and "The Bride Wore Black" (1968), accompanied Leaud to New York in April to promote the Truffaut retrospective, which debuted there.

"The relationship between us was very, very, very strong," said Moreau, in her lustrous, gravelly timbre. She claimed not to be one of Truffaut's sexual conquests.

Bedecked with a fuchsia scarf, and wearing lipstick-red lace-up boots, dark brown slacks and a tweed jacket, Moreau was still very much the screen diva.

When Truffaut invited her to star as Catherine, the sirenlike object of two men's affections in "Jules and Jim," Moreau was already a well-established actress.

But the social dance that typically occurred between Truffaut and his actresses would be different this time.

"Luckily, we were not lovers," Moreau said. "Passion distorts things. There was a very powerful attraction, but it was an exchange of fascination and curiosity. We taught one another lots of things and we did things together without the pressure, the delusion, or the deception . . .

"But clearly he dealt with his obsessions--his films and the women he was fascinated with: Fanny Ardant, Deneuve, Isabelle Adjani, Francoise Dorleac, Marie Dubois, Bernadette Lafont. Women were very, very important. And cinema. He's the one who said life in films was better than in real life."

Moreau met Truffaut in 1957 when he was a critic for Cahiers du Cinema, the film magazine founded by his mentor, Andre Bazin, and Arts-Lettres-Spectacles, a right-wing periodical that allowed Truffaut to print his most scathing attacks.

By then, he had already made a name for himself by declaring open season on the French filmmaking establishment. He launched regular attacks on those filmmakers he considered fatuous and overly dependent on literary works.

He also evolved his "politique des auteurs," the so-called auteur theory which, essentially, elevated the director as the sole "author" of a movie, as opposed to the writer, producer or actors. After all, Truffaut argued, it was the director who arranged the actors and scenery (the mise en scene); and it was the director's vision and thematic concerns that really informed the movie.

His prolific, caustic critiques, as well as his blatant championing of "true auteurs"--ranging from Jean Renoir to Vincente Minnelli--turned film reviewing into an art form, not to mention an ideological war.

Jean-Luc Godard, Claude Chabrol, Eric Rohmer, Jacques Rivette and other spirited polemicists and aspiring filmmakers eagerly joined in the fray. And Truffaut found himself at the head of a movement.

But more and more, Truffaut realized he wanted to be a filmmaker. After many false starts, including many aborted projects as an assistant to Italian director Roberto Rossellini, Truffaut finally received backing for a 1957 short called "Les Mistons."

The story of a gang of kids who become jealously hostile toward a pair of young lovers, it heralded one of Truffaut's staple themes: the life of the child. Following the modest, critical success of "Les Mistons," Truffaut--with help from his father-in-law--made "The 400 Blows."

The success at Cannes launched filmmaking careers for Truffaut and Leaud and a lifelong friendship. Leaud played Doinel in four subsequent films, including "Stolen Kisses" (1968) and the 1979 final installment, "Love on the Run."

Truffaut, who ultimately had three daughters (two with Morgenstern and a third with Ardant), looked after Leaud's living and schooling arrangements through his adolescence and remained an adviser for his artistic projects.

"I was a very bad student," recalled Leaud, now 54, of his first encounter with Truffaut in 1959. "I was kicked out of maybe 12 or 18 schools. Adults were always tough with me. But Truffaut loved children and understood them very well."

Leaud was amazed, he said, at the sudden importance he commanded as lead actor. For the boy whom one peeved principal had described as "emotionally disturbed," this was a first-time experience.

"The moment I was on the set and about to deliver my lines, everyone said, 'Silence!' I was just a young boy, and I thought it was funny that whenever I was about to speak, everyone said, 'Silence! Jean-Pierre's about to speak.' "

Truffaut, said Leaud, "was my mentor, my best friend, and the greatest film director in French cinema." Although he was to make many films with Godard, Jean Eustache and others, Leaud added, one movie remains his most precious: "Definitely the first. Definitely 'Les Quatre Cents Coups.' "

Although Truffaut's career was uneven, he enjoyed enough critical and commercial success to create a mystique in Europe and around the world, including Japan. He was a darling of the American critical establishment, too. Film programmer Richard Roud frequently invited Truffaut to show his films at the New York Film Festival.

"The 400 Blows" was nominated for Best Screenplay at the 1959 Oscars. "Stolen Kisses" was nominated for Best Foreign Movie in 1968. And Truffaut finally won the foreign Oscar for 1973's "Day for Night."

To his cinephile fans--many of whom would become filmmakers themselves, from Paul Mazursky to Steven Spielberg--Truffaut brought a uniquely European passion and childlike sensibility to the screen.

A neglected child given to lying, stealing and keeping to himself, Truffaut--by his own estimate--saw more than 4,000 films between 1940 and 1955. Like Spielberg (who would cast his idol in "Close Encounters of the Third Kind"), Truffaut was the grown-up child of the movies. It was only logical he would make films, too.

Truffaut drew from his experiences for stories about children and their separate existence from the world of adults. The life of the child figured large in "Les Mistons," "The 400 Blows," "The Wild Child" (1970) and "Small Change" (1976).

And Truffaut limned the sexual, emotional yearnings of men and women in most of his films, including the Antoine Doinel series; "Jules and Jim"; "The Story of Adele H.," in which Adjani played a daughter of Victor Hugo, obsessed with an English officer; "The Man Who Loved Women"; and "The Woman Next Door" (1981), in which Ardant has an affair with old flame Gerard Depardieu, who is now married with children.

But the box office failures, including "The Wild Child" and "The Man Who Loved Women," took their emotional toll on Truffaut, who was constantly worried about losing money for his production company, Les Films du Carosse--the production arm the Morgensterns helped form.

"Shoot the Piano Player," a playful film noir starring Charles Aznavour, failed to attract the praise Truffaut felt it deserved. "The Bride Wore Black" and "Mississippi Mermaid" suffered similar reactions. And one of Truffaut's worst failures was "Fahrenheit 451," an adaptation of the Ray Bradbury novel and his only English-language film, which lost a great deal of money. To make matters worse, while still considering the Bradbury project, Truffaut dithered over and finally rejected an offer to direct "Bonnie & Clyde."

A schism in the Cahiers camaraderie occurred when Godard wrote Truffaut to express his disgust with "Day for Night," a movie about the making of a film in which every character on the set but the director seems to be having affairs. Given Truffaut's real-life personality, Godard considered this an act of artistic deception.

Audaciously, Godard also asked Truffaut in the same letter for some money for a film project. Truffaut, who had started Godard's career by writing the original treatment for his first film ("Breathless"), was outraged. The two friends barely spoke to each other again.

Despite his womanizing, Truffaut managed always to maintain serial relationships. He was nothing if not a machine, in his artistic and personal life--compartmentalizing his lovers from each other, and organizing his films sometimes years ahead of schedule. Good or bad, Truffaut's films ran like clockwork, although his output in his later years was adversely affected by bouts of depression.

When Truffaut was diagnosed with a brain tumor, Ardant was pregnant with his child. He held on with determination, a significantly relaxed production schedule and great humor, but Truffaut could only delay the inevitable. On his last day, according to "Truffaut: A Biography," his ex-wife Madeleine and their two daughters were present as well as Ardant. The man who loved women finally died surrounded by them.

In New York, Leaud summed up the emptiness he continues to feel after Truffaut's death.

"What bothers me the most is not being able to go and see Truffaut's latest film anymore. Because he had planned many other films. It's terrible that he has disappeared just like that."

Said Moreau: "I don't live a day without being with Francois. He's kept alive by the fact that these films are shown, that I meet you, and we talk about him. I live as much with my dead friends as with the living. The phrase 'Till death do us part,' I don't believe it. When you have a profound attachment, you don't part."

'TOUT TRUFFAUT' AT AFI, NATIONAL GALLERY

The American Film Institute and the National Gallery of Art are showing "Tout Truffaut: The Films of Francois Truffaut." English titles are followed by French in parentheses.

AMERICAN FILM INSTITUTE:

Friday at 6:30 p.m.; Saturday at 10 p.m.; Aug. 1 at 1 p.m. and 9:30 p.m.: "Jules and Jim" (Jules et Jim) (1962, 110 minutes).

Saturday at 2 and 8; Aug. 1 at 7:30: "The Bride Wore Black" (La Mariee Etait en Noir) (1968, 110 minutes).

Saturday at 4 and 6; Aug. 1 at 5:30: "Fahrenheit 451" (1966, 110 minutes).

Aug. 6 at 6:30; Aug. 7 at 4:15 and 9:45; Aug. 8 at 9:45: "Shoot the Piano Player" (Tirez Sur le Pianiste) (1960, 80 minutes).

Aug. 6 at 8; Aug. 8 at 7:15: "Two English Girls" (Les Deux Anglaises et le Continent) (1971, 132 minutes).

Aug. 7 at 5:45; Aug. 8 at 5:30: "Stolen Portraits" (Portraits Voles) (1993, 93 minutes), documentary about Truffaut by Serge Toubiani and Michel Pascal.

Aug. 7 at 7:30; Aug. 8 at 1: "Mississippi Mermaid" (La Sirene du Mississippi).

Aug. 16 at 9; Aug. 18 at 9: "The Woman Next Door" (La Femme d'A Cote) (1981, 106 minutes).

Aug. 17 at 9; Aug. 19 at 9: "Such a Gorgeous Kid Like Me" (Une Belle Fille Comme Moi) (1972, 100 minutes).

Aug. 20 at 6:30; Aug. 21 at 7; Aug. 22 at 6:30: "The Story of Adele H" (L'Histoire d'Adele H) (1975, 97 minutes).

Aug. 27 at 8:15; Aug. 28 at 8:30: "The Last Metro" (Le Dernier Metro) (1980, 133 minutes).

Aug. 28 at 6:30; Aug. 29 at 1: "Confidentially Yours" (Vivement Dimanche) (1983, 111 minutes).

NATIONAL GALLERY OF ART:

Aug. 1 at 4; Aug. 7 at 2:30: "Les Mistons" (1957, 20 minutes) and "The 400 Blows" (Les Quatre Cents Coups) (1959, 101 minutes).

Aug. 8 at 4: "Antoine et Colette." (1962, 29 minutes) and "Stolen Kisses" (Baisers Voles) (1968, 90 minutes).

Aug 14 at 2: "Bed and Board" (Domicile Conjugal) (1970, 100 minutes) and "Love on the Run" (L'Amour en Fuite) (1979, 95 minutes).

Aug. 15 at 4: "The Wild Child" (L'Enfant Sauvage) (1970, 85 minutes).

Aug. 21 at 1:30 and 3:45: "Day for Night" (La Nuit Americaine) (1973, 115 minutes).

Aug. 22 at 4: "The Soft Skin" (La Peau Douce) (1964, 115 minutes).

Aug. 28 at 2: "The Green Room" (La Chambre Verte) (1978, 94 minutes) and "Small Change" (L'Argent de Poche) (1976, 105 minutes).

Aug. 29: "The Man Who Loved Women" (L'Homme Qui Aimait les Femmes) (1977, 119 minutes).