This is a momentous week for Hollywood anniversaries as 5 August saw half a century pass since the sad death of Marilyn Monroe, while 12 August will mark the centenary of Gene Kelly. As Kelly was based at Metro-Goldwyn-Mayer and Monroe spent much of her career at Twentieth Century-Fox, they never got to work together, although Kelly did make a cameo appearance in George Cukor's musical comedy Let's Make Love (1960), as Yves Montand's billionaire playboy seeks advice from Kelly, Bing Crosby and Milton Berle on how to dance, sing and tell jokes in order to win the heart of Marilyn's off-Broadway showgirl.

As a mainstay of the MGM musical as both actor and director, Kelly clearly made the greater artistic contribution to American cinema. But Monroe remains its undisputed pin-up queen, with only James Dean rivalling her in iconic status among the superstars who died tragically young. Had she lived, Marilyn would she would be the same age as Elizabeth II. But the psychological fragility that made her private life so tortuous is readily evident on the screen and it's fascinating to compare her performances with those of Kelly's frequent co-star Judy Garland, who would have been 90 in June had she not followed Monroe in succumbing to an overdose of barbiturates on 22 June 1969.

Born in Pittsburgh in 1912, Gene Kelly performed in university productions and worked in his mother's dance studio before getting his Broadway break in Leave It to Me (1938). Stage fame came with Pal Joey (1940) and he played another everyman with everyday foibles and a supercilious, cynical streak in his MGM debut, For Me and My Gal (1942), which saw him team with Garland for the first time.

Indeed, the tempering of ego was to become a key theme of Kelly's films. Handsome, lithe, charming and ambitious, he often came across as a childlike clown seeking to prolong his carefree existence. Consequently, he was more comfortable dancing with kids or his buddies than with female partners and his duets with Rita Hayworth, Vera-Ellen, Cyd Charisse and Leslie Caron lacked genuine intimacy.

If anything, Kelly was happiest dancing with props - a soda fountain and a mop in Thousands Cheer (1943); his own reflection in Cover Girl (1944); cartoon characters in Anchors Aweigh (1945) and Invitation to the Dance (1956); a dog, a statue and an unfinished building in Living in a Big Way (1947); a ship in a Caribbean port in The Pirate (1948); museum exhibits in On the Town (1949); a squeaky floorboard and a newspaper in Summer Stock (1950); his bedsit in An American in Paris (1951); an umbrella and a streetful of puddles in Singin' in the Rain (1952); and a bin lid and some rollerskates in It's Always Fair Weather (1955).

He also danced with Fred Astaire in `The Babbit and the Bromide' sequence in Ziegfeld Follies (1946). But their styles could not have been more different. Whereas Astaire was influenced by the ballroom tradition, Kelly exuded both a buck-and-winging burlesque swagger and an athleticism that first emerged as an ice hockey player. Tellingly, he later championed the sportiness of dance in his celebrated tele-documentary, Dancing - A Man's Game (1958).

`I have a lot of [George] Cohan in me,' Kelly once revealed `It's an Irish quality, a jaw-jutting, up-on-your toes cockiness - which is a good quality for a dancer to have.' He certainly had a virtuosity that gave his work a macho flamboyance that contrasted with Astaire's easy sophistication. They even sang and dressed differently, with Kelly being casual where Astaire was precise.

Astaire epitomised the elegant individualism of the Jazz Age, while Kelly embodied the vigour and confidence of postwar America. Thus, while Astaire danced in seclusion, Kelly burst out on to the streets to express his joie de vivre. Consequently, his choreography was always linked to character and plot, although it also often had a balletic affirmation that made it so unique.

Yet Kelly also possessed a noirish spirit and his flawed characters chimed in with the Cold War's doubting shamus, psychological cowboy and reluctant war hero. Moreover, he was prone to showboating and occasionally overbalanced the scenario with his exuberant egotism and hankering to create dream balletic art. Consequently, his work never seemed as spontaneous as Astaire's, although he was more cinematic, as he realised that the lens flattens dance on the screen and sought innovative ways of using camera movement, visual effects, stylised sets and authentic locations to recreate the kinetic energy and three-dimensionality of a performance.

Although he continued to contribute to songbook pictures like Words and Music (1948) and Deep in My Heart (1954) and headline musical originals (Take Me Out to the Ball Game, 1949) and adaptations (Brigadoon, 1954), Kelly was also keen to flex his non-musical muscles. Consequently, he proved surprisingly effective as the charming killer opposite Deanna Durbin in Christmas Holiday (1944), the headstrong D'Artagnan in the pseudo-balletic swashbuckler The Three Musketeers (1948) and the cynical journalist in the Scopes `Monkey' Trial recreation Inherit the Wind (1960).

He had also established himself as a decent director, in collaboration with Stanley Donen. So, with audiences now preferring rebels to rascals, Kelly left MGM after Les Girls (1957) and contented himself with guest appearances in the likes of Let's Make Love, What a Way to Go! (1964), Les Demoiselles de Rochefort (1967), 40 Carats (1973) and Xanadu (1980), while concentrating on directing such contrasting musicals as Flower Drum Song (1962) and Hello, Dolly (1969).

Currently, Christmas Holiday, Cover Girl, Anchors Aweigh, The Three Musketeers, Let's Make Love, Inherit the Wind, What a Way to Go! and Xanadu are all available on disc. But let's focus on four films in detail.

Directed by Vincente Minnelli, The Pirate ranks among the musical's most maligned masterpieces. It was based on Ludwig Fulda's 1911 play, Der Seerauber, which had been adapted by SN Behrman as a comedy for the husband-and-wife team of Alfred Lunt and Lynn Fontanne in 1942. MGM had acquired the rights for screenwriter Joseph L. Mankiewicz to concoct an 1830s romance for Judy Garland, in which an entertainer poses as a pirate to steal a Caribbean beauty from a duplicitous mayor. But, Lemuel Ayers, who had designed the Broadway original, suggested that it would work better as a Cole Porter musical and producer Arthur Freed concurred.

However, Freed was so dismayed by the first four songs that Porter submitted that he rejected them, along with a script by Anita Loos and Joseph Than. Subsequently, Frances Goodrich and Albert Hackett were drafted in to collaborate with Porter and Minnelli to integrate the score into the scenario, in order to lampoon the conventions of operetta while also celebrating their theatricality. Refusing to shoot on location, Minnelli also had art director Jack Martin Smith blend Latin American and West Indian styles to achieve the conscious artificiality that was to be the film's leitmotif, as this was a study in illusion.

Manuela (Garland) thinks she's in love with the notorious brigand Mack `the Black' Macoco, but she's really only enamored of his dashing image in a book. Unsurprisingly, therefore, she falls for Serafin (Kelly), a ham actor masquerading as her hero rather than the buccaneer himself, who is actually the corpulent Don Pedro (Walter Slezak), whom her Aunt Inez (Gladys Cooper) wishes her to marry.

However, it takes Manuela's entry (under Serafin's hypnosis) into another dream world to reveal these suppressed desires and belt out `Mack the Black' with a passion that thrills both the diegetic onlookers and the film audience, who not only share her willingness to be transported to a place of escape and romance, but who are similarly ready to be mesmerised by the action on the screen.

This is, therefore, a classic Hollywood paean to show business. It's also a fine example of the fairytale musical (albeit with a little backstager morality thrown in), as Manuela chooses the itinerant troubadour over the seeming respectability of wealth, while Serafin appears content to abandon his philandering ways to settle down with his true love.

The production itself ended less happily, however. The Pirate placed huge demands on Garland, as she not only had to combine dramatic intensity with comic finesse, but she also had to sing Porter with passion and keep step with Kelly - and all at a  time when she was struggling to cope with the birth of her daughter Liza, the terminal decline of her marriage to Minnelli and the onset of a breakdown that she kept at bay with pills. Consequently, she buckled under the strain and missed 99 of the 135 shooting days before checking into a sanatorium.

Yet, she somehow managed to produce a fine performance, excelling particularly on `Love of My Life', `You Can Do No Wrong' and `Mack the Black'. She even held her own with Kelly on the reprise of `Be a Clown', which he had earlier insisted on performing with the African-American Nicholas Brothers, despite the sure knowledge that the number would be cut in the Deep South, where audiences refused to watch routines featuring black talent either in isolation or alongside the movie principals.

However, Garland's luminous display owed much to Harry Stradling's chivalrously sensitive cinematography, which managed to make her look as glamorous as the sumptuous sets, which were seen at their Technicolor best in `Nina' and `The Pirate Ballet', which were impeccably edited by Blanche Sewell to capture the full exuberance of Kelly's mischievous impersonations of such dashing screen heroes as Douglas Fairbanks and John Barrymore.

Yet, neither this glorious artistry nor the gleeful fantasy found public favour and The Pirate earned only $2,956,000 on its $3,766,396 budget, making it Garland's only MGM movie to lose money. Freed suggested that it was 20 years ahead of its time. But studio chief Louis B. Mayer shared Time magazine's verdict that this was `entertainment troubled by delusions of art' and he rushed Kelly and Garland into Easter Parade in a bid to restore their wholesome reputations. Unfortunately, however, Kelly would fracture his ankle playing ball and he was replaced by his mentor, Fred Astaire.

The break would give Kelly the opportunity to develop his first directorial project and On the Town would set a new agenda for the Hollywood musical. In his seven years at MGM, Kelly had realised that the techniques used to record song musicals were wholly inappropriate to the filming of dance. He was determined to capture the kinetic energy of live performance and, in order to do so, he had to reinvent the art of screen choreography.

Indeed, Kelly set out to create a masterpiece and sought to give it a distinctly proletarian sensibility  by concentrating on three average sailors and the hard-working city girls they meet during a 24-hour furlough. He even achieved a novel sexual equality by having Betty Garrett and Ann Miller make all the running with Frank Sinatra and Jules Munshin, while his own obsession with Vera-Ellen's Miss Turnstiles owed as much to her cultural and sporting aptitude as to her celebrity or looks.

Kelly and co-director Stanley Donen also challenged the conventions of mainstream storytelling by shooting on location, dislocating the narrative and compressing time and space to give the action an urgency that equated to modern urban living. They even included regular on-screen time checks to emphasise the immediacy of Kelly's race to find Vera-Ellen before he has to return to his ship.

Yet this landmark picture met opposition at every stage. Even though he had followed Arthur Freed's advice and purchased the rights during pre-production, Louis B. Mayer branded the original 1944 Broadway show `smutty' and `Communistic' and the project was shelved until Kelly insisted on its revival. Freed himself has misgivings about Leonard Bernstein's score, whose origins lay in the ballet Fancy Free, which he had composed in mid-1944 for choreographer Jerome Robbins. Thus, Freed dispensed with the more avant-garde items and teamed screenwriting lyricists Betty Comden and Adolph Green with associate producer Roger Edens to create something catchier and more cinematic.

Meanwhile, Mayer was baulking at the expense involved in shooting on the East Coast and limited Kelly and Donen to a mere five days on location. Yet, they overcame bad weather and considerable technical difficulties relating to playbacks and synchronisation to achieve an impressionistic `city symphony' that conveyed a tourist's excitement, while also capturing a sense of the everyday. Much of this was down to editor Ralph E. Winters, who most notably packed three-and-a-half diegetic hours and 18 locations into the two-and-a-half-minute opening number, `New York, New York'.

This vibrancy also informed the other musical stagings. Kelly experimented with a dazzling variety of dance styles, including ballet, soft-shoe, ethnic, tap and comic hoofing, and choreographed Harold Rosson's camera to match the vigour of the routines. Thus, he used all manner of dollies, cables and cranes to make the moving camera a partner in the dance rather than a detached spectator. Moreover, he frequently shot in long takes to make innovative use of angle and space. But when he did cut, he did so on action to open up new expanses for the cast to conquer.

Indeed, such was the emphasis on dance that all but Kelly and Vera-Ellen were replaced by professional dancers for the `Day in New York' ballet, which took a sizable risk in asking audiences to accept that Kelly's macho, wisecracking gob would have a balletic soul. But he pulled it off with typically bullish bravado and secured screen dance a new athletic appeal that came to characterise his unique brand of choreography.

Yet, the MGM brass felt that On the Town was too different from the usual studio fare and was convinced it would fail. However, it grossed $4.4 million on its $2,111,250 budget and won the Oscar for the Best Scoring of a Musical Picture. Moreover, it proved conclusively that musicals didn't have to be about show people, but could focus on ordinary folk who sang and danced on actual streets because they had no other way of expressing themselves. Thus, the old backstage format went into abeyance for much of the genre's last golden decade - although there were glorious exceptions, like Singin' in the Rain (1952) and The Band Wagon (1953), in which Fred Astaire was directed by Vincente Minnelli.

While Kelly and Donen were preoccupied with their debut, Arthur Freed was taking advantage of one of his regular games of pool with lyricist Ira Gershwin to secure permission to create a musical from his brother George's 1928 composition, An American in Paris.

Back in 1937, Samuel Goldwyn had dropped a George Balanchine ballet based on the score from The Goldwyn Follies because `the miners in Harrisburg won't understand it'. But Kelly and Vincente Minnelli were intent on proving that film was not merely escapist entertainment, but was legitimately the Seventh Art. Thus, in their hands, the story of a GI bent on becoming an artist was fashioned into a cinematic tone poem by the fusion of music, design and performance.

Sally Forrest, Cyd Charisse and Odile Versois were all considered for the role of Lise, the gamine who steals Kelly's heart. But he had seen Leslie Caron dancing on stage as a 15 year-old and was convinced that she had the necessary innocence and balletic technique to play the war orphan who enchants Jerry Mulligan, a genial emigré who only comes to terms with himself and his talent through her love. Carl Brisson and Maurice Chevalier were mooted for vaudevillian Henri Baurel. But the part went to Georges Guetary (who was renowned as the French Fred Astaire) after the conceited Chevalier refused to lose the girl.

Lyricist Alan Jay Lerner was hired to write a scenario that could accommodate highlights from the Gershwin songbook at key dramatic and psychological points in the narrative. But the music also had the dual responsibility of reinforcing the picture's bid for universal appeal by combining Americans and Europeans, the young and the old, the concert hall and the music-hall, friendship and romance, and the populist and the highbrow. An American in Paris was, therefore, conceived as a film of set-pieces, each of which flowed from the storyline while remaining entirely individual. Kelly's rendition of `I Got Rhythm' with some street kids, for example, contrasted charmingly with his exhilarating duets with Guetary (``S Wonderful') and Oscar Levant (`By Strauss') and his serenade of Caron with `Our Love Is Here to Stay'.

But the showstoppers were even more consciously ingenious, with a grand Folies-Bergère staircase with illuminated steps being created for Guetary's `I'll Build a Stairway to Paradise', while deft process photography was used to enable both the six facets of Lise's personality to appear simultaneously during `Embraceable You' and Levant to play the entire orchestra and audience on the Third Movement of Gershwin's Concerto in F. However, nothing matched the scope, refinement and sheer audacity of the `American in Paris' ballet, which lasted an unprecedented 16 minutes and 37 seconds. Meticulously designed by Irene Sharaff and Preston Ames and photographed by John Alton with a smoky quality that enhanced the pastoral shades, the ballet was a Hollywood tribute to the spirit that inspired both the Impressionists' art and Gershwin's music.

Each location evoked the style of a specific painter - Dufy (Place de la Concorde), Renoir (Le Madeleine flower market), Utrillo (a street carnival), Rousseau (Jardin des Plantes), Van Gogh (Place de l'Opéra) and Toulouse-Lautrec (Montmartre) - while Kelly switched brilliantly between classical and modern ballet, Cohanesque hoofing, tap, jitterbugging and athletic exuberance to counterpoint the character of the visuals and create `a synthesis of old forms and new rhythms'.

Taking six weeks to rehearse (during which time Minnelli made Father's Little Dividend, 1951) and a month to shoot, the ballet accounted for $542,000 of the $2,723,903 budget. But while this Technicolor extravaganza grossed in excess of $8 million, some critics complained about its lack of humour and surfeit of calculated sophistication.

Yet Minnelli and Kelly had set out to make a serious musical and they certainly impressed their peers, who rewarded them with six Oscars from eight nominations, including Best Picture. Moreover, Kelly received an honorary award `in appreciation of his versatility as an actor, singer, director and dancer, and specifically for his brilliant achievements in the art of choreography on film'.An American in Paris saw the MGM musical finally become an artform. But, within a decade, it was to become an anachronism, notwithstanding the exhilarating brilliance of Singin' in the Rain.

In 1982, this joyous picture came second to Orson Welles's Citizen Kane (1941) in Sight and Sound's decennial poll of the best films of all time. The ultimate self-reflexive mythologising genre picture, it's a history of the MGM musical and lyricist-producer Arthur Freed's part in its evolution. Consequently, it's anything but original. Indeed, it's essentially a Stateside variation on An American in Paris, with Hollywood replacing the City of Light, movies supplanting paintings, and the songbook of Arthur Freed and Nacio Herb Brown superseding that of the Gershwins. Moreover, the emphasis was on performance rather than psychology and on representation rather than evocation and, thus, it was seen as studio prose instead of auteur poetry and as musical entertainment not screen art.

Yet its enduring appeal lies precisely in its derivative reconstruction of a bygone age of cinematic  innocence. Most of the incidents relating to the problem of sound recording were based on fact and several of the characters were modelled on Hollywood legends. The songs were similarly lifted from past MGM hits, while dance routines like `Beautiful Girl' borrowed from other studios in paying homage to both Busby Berkeley's kaleidoscopic patterns and the fashion shows mounted in Roberta (1935) and Cover Girl (1944). Even the supposedly original `Make `Em Laugh' unintentionally plagiarising Cole Porter's `Be a Clown' from The Pirate (1948).

Many of the props were recycled, too, although much of the primitive sound equipment had to be researched and recreated, as it had become obsolete in the quarter-century since Talkies had terrorised Tinseltown. However, the coming of sound wasn't the first topic to strike screenwriters Betty Comden and Adolph Green. Indeed, they had been contemplating a Howard Keel vehicle about a 1930s singing cowboy before Kelly came on board and the concept shifted to a dance picture set in the wake of The Jazz Singer (1927).

This backdrop enabled Kelly and co-director Stanley Donen to play lots of audiovisual games, in which sound and image were frequently out of sync. The opening montage chronicling Don Lockwood's early career, for example, bears no resemblance to the story he spins for the listening radio audience. But the slyest in-joke lay in the dual deceit of having Jean Hagen (Lina Lamont) actually deliver some of the dialogue that was supposedly being dubbed by Debbie Reynolds (Kathy Selden), whose singing voice was provided by Betty Royce.

Indeed, the 19 year-old starlet had a tough time throughout the shoot, as Kelly rehearsed her hard to atone for the deficiencies in her dance technique. He had no such problems with Donald O'Connor, however, whose knockabout performance on `Make `Em Laugh' ranks as highly as Kelly's own on `Singin' in the Rain', which not only celebrated Don's new love, but also the realisation that the Talkie atrocity, The Duelling Cavalier, could be saved by transforming it into a musical comedy.

This sparkling routine recalled the old backstager tactic of linking courtship to the success of the show and vaunting the triumph of entertainment over art. Yet it also alluded to the fairytale tradition of having a footloose character find stability in emancipating a timid lover (see page 00). But, most significantly, the number typified the feature's bold exploitation of the confines of the soundstage and the frame, and its use of film iconography, the unique ellision of time and space, and the benefits of technical magic to tell its story in a fluent and wholly cinematic manner.

But the dream ballet exposes Kelly's limitations as a director, as his use of light, colour and design during its 12 minutes and 57 seconds is markedly less innovative than Vincente Minnelli's in either The Pirate or An American in Paris. Moreover, it's less narratively taut than the `Slaughter on Tenth Avenue' routine that Kelly had produced for Words and Music (1946). However, it did provide a nostalgic summation of MGM's Broadway Melody series and made a star of Cyd Charisse, as the vamp who dumps Kelly's wannabe hoofer for a diamond-toting mobster.

Although it sadly dropped out of the Sight and Sound Top 10 earlier this month, Singin' in the Rain has lost little of its popularity since returning a gross of $7,665,000 on its $2,540,800 budget. Indeed, its influence can readily be seen in Michel Hazanavicius's Oscar-winning homage to the same period, The Artist. But it proved to be the peak of Kelly's creativity and his career rather tailed off before he left MGM five years later.

In the five decades since her death, none of Marilyn Monroe's many biographers has come remotely close to fathoming this blonde enigma or explaining her tragic demise at the age of just 36. Yet such is the potency of Monroe's enduring appeal and the undisputed sadness of her story that she remains a tantalising figure. It is often claimed that Monroe's men ultimately drove her to despair, but the women of her youth certainly helped set Norma Jean on the road to ruin. Both her grandmother Della and her mother Gladys claimed to have heard voices and experienced paranoid delusions. But, although she spent a year in the Los Angeles Orphans' Home, Monroe seems to have been cherished by foster mother Ida Bolender and by Gladys's friend Grace McKee Goddard and her aunt, Edith Ana Lower. Indeed, they encouraged her to follow her dream of making it in show business and kindled within her the steely determination that would enable her to achieve stardom, albeit via the most circuitous and often demeaning of routes.

Born in Los Angeles on 1 June 1926, Norma Jean Mortenson saw little of Gladys Baker (who was a negative cutter at Columbia and RKO) because of her mental health issues and she was raised in a succession of orphanages and foster homes. In 1945, the 16 year-old married neighbour Jim Dougherty and began posing for morale-boosting pin-ups when she was spotted by Army photographer David Conover. Briefly adopting the name Jean Norman, she began modelling full time in 1946 and was signed to Twentieth Century-Fox under the name Marilyn Monroe (which was her grandmother's surname).

Following six months of starlet training, Marilyn made her screen debut with an uncredited bit in Scudda-Hoo! Scudda-Hay! (1948), but she could only seen in a distant long shot after the other footage in which she had appeared was cut. In spite of having an affair with studio bigwig Joseph M. Schenck, she was dropped after featuring in Dangerous Years (1948) and began taking lessons at the Actor's Lab under Method guru Morris Carnovsky.

She debuted on stage in Glamour Preferred (1947) and briefly entered into a `management' arrangement with John Carroll before finally landing the notable role of Peggy Martin in Columbia's Ladies of the Chorus (1948), in which she sang on screen for first time. Yet, Monroe was soon forced to return to modelling and even posed for a nude calendar and participated in a 1949 striptease smoker.

Determined not to abandon her acting ambitions, however, she was rediscovered by William Morris agent Johnny Hyde and cast as Angela Phinlay in John Huston's The Asphalt Jungle (1950). Hyde also exploited his contacts at MGM and Fox and Monroe caught the eye as Miss Caswell in Joseph L. Mankiewicz's Oscar-winning All About Eve (1950). Yet, while she continued to study under Stanislavsky disciple Michael Chekhov, Monroe became a star through a combination of her looks and a willingness to trade on her sensual vulnerability.  Nevertheless, she also developed her inimitable comic gifts in entertainments like Howard Hawks's Monkey Business (1952) and Gentlemen Prefer Blondes (1953) and her deceptive dramatic depth in Henry Hathaway's Niagara (1953).

In 1954, Monroe married baseball icon Joe DiMaggio, only for the marriage to end 10 months later, by which time Monroe has become an international sex symbol, thanks to her encounter with a New York air vent in The Seven Year Itch (1954). Her refusal to be typecast in ditzy blonde roles, however, led to Fox suspending her and she used the downtime to set up Marilyn Monroe Productions and to enrol in the Actors Studio, where she fell under the influence of Lee and Paula Strasberg.

She also met and married playwright Arthur Miller and her brush with the East Coast intelligentsia led to Fox welcoming her back with an improved and non-exclusive contract. Having garnered critical acclaim for her display as Cherie in Bus Stop (1956), she travelled to Britain to co-star with director Laurence Olivier in The Prince and the Showgirl (1957) - with the story of the shoot eventually inspiring Simon Curtis's One Week With Marilyn (2011), which starred Michelle Williams as Monroe, Kenneth Branagh as Olivier and Eddie Redmayne as Colin Clark, the assistant on the set who became her confidant.

Back in Hollywood, Monroe surpassed herself as Sugar Kane Kowalczyk opposite Tony Curtis and Jack Lemmon in Billy Wilder's sublime comedy Some Like It Hot (1959). But Monroe became increasingly dependent upon pills and alcohol after she miscarried and her marriage to Miller began to unravel. Increasingly prone to depression, she suffered a breakdown shortly after completing John Huston's The Misfits (1961), with her girlhood idol, Clark Gable. Yet she recovered sufficiently to accept the lead in Something's Gotta Give, only to be fired for her unreliability. A few days later, she was found dead in her Brentwood home at the age of 36 from acute barbiturate poisoning, which was presumed by the coroner to have been self-inflicted.

Conspiracy theories have abounded ever since that Monroe was murdered because of her liaisons with President John F. Kennedy and his younger Attorney General brother Robert. But rumours of FBI, Comintern and/or Mafia involvement have never been proven. But, while some have insisted that Marilyn had become tired of playing the most demanding role of her career, we shall never know whether she died deliberately or accidentally. What is not in dispute, however, is that Marilyn remains one of the most recognisable faces in screen history and critics have subsequently come to recognise the deceptive quality of her acting.

Numerous Monroe movies have been released on DVD, with As Young As You Feel, Let's Make it Legal, Love Nest (all 1951), Don't Bother to Knock, We're Not Married!, Monkey Business (all 1952), Niagara, How to Marry a Millionaire (both 1953), River of No Return, There's No Business Like Show Business (both 1954), Bus Stop (1956), Some Like It Hot (1959) and The Misfits (1961) all being available on their own or in boxed sets. As with Kelly, however, we shall concentrate on four films, two of which contain scene-stealing minor roles that set Marilyn on the road to stardom.

John Huston is widely credited with bringing film noir to American screens with The Maltese Falcon in 1941. In that same year, he adapted WR Burnett's pulp novel High Sierra as a vehicle for Humphrey Bogart and he returned to the same author (who had also helped script the gangster classics Little Caesar and Scarface) for the prototype heist movie, The Asphalt Jungle (1950).

Co-scripting with Ben Maddow, Huston achieved a tangible sense of postwar anxiety and urban grit by borrowing from both the noir tradition and the voguish brand of ultra-realist problem picture exemplified by the 1949 race drama Intruder in the Dust (which Maddow had adapted to considerable acclaim from William Faulkner's novel). The story centres on Sam Jaffe as he leaves jail and assembles a gang comprising Kentucky thug Sterling Hayden, hunchbacked getaway driver James Whitmore and safe-cracker Anthony Caruso to execute a long-planned jewellery heist. However, no one trusts fence-cum-lawyer Louis Calhern and suspicion and caprice ensure that the meticulous scheme soon begins to unravel.

Yet while the settings and dialogue were abrasively authentic, Huston couldn't resist empathising with the various losers against whom fate was about to conspire. Hayden is portrayed as a big lug who wants to buy back his father's horse ranch; Whitmore is a cat lover and Caruso has a family to feed. Similarly, the crooks' women - Hayden's loyal girlfriend Jean Hagen), Caruso's spouse Teresa Celli and Calhern's wife, Dorothy Tree, and his gold-digging mistress, Marilyn Monroe- are anything but the usual femmes fatale.

Thus, the law-breakers are presented as anti-heroes rather than villains and their crime is considered more an act of desperation than greed. Yet once Jaffe's plan begins to fall apart, there proves to be little honour among the thieves and their camaraderies turns out to be as brittle as the morality of the cops set to watch over this hopelessly corrupted society.

A seminal influence on crime pictures to this day, The Asphalt Jungle has been remade three times (but never well), as a Western (The Badlanders, 1950), a caper (Cairo, 1963) and a blaxploitation thriller (Cool Breeze, 1972). Given Hollywood's current reliance on recycling classics, don't be too surprised if it resurfaces in another guise some time soon.

With cinema losing its battle with television, it was no coincidence that two such rancorous exposés of  Hollywood and Broadway as Sunset Blvd. and All About Eve should have been up against each other for the Best Picture of 1950. Eve landed 14 nominations, a record that was not equalled until Titanic in 1998. Its four female stars were all cited - Bette Davis and Anne Baxter for Best Actress and the late Celeste Holm and Thelma Ritter for Best Supporting - and although they all lost out (to Judy Holliday in Born Yesterday and Josephine Hull in Harvey, respectively), the picture was successful in six other categories, notably bagging a brace for writer-director, Joseph L. Mankiewicz.

Having seen his brother Herman win an Oscar for his screenplay for Citizen Kane (1941), Mankiewicz borrowed elements from its winning, flashbacking formula for this showbiz bitchfest, which sought to understand what drove Anne Baxter's aspiring actress to clamber to the top over the corpse of her supposed idol, Bette Davis.

Based on Mary Orr's short story and radio play, The Wisdom of Eve, this has none of the enduring class of Kane, as Joseph is nowhere near as dexterous a writer as his older sibling (with too many of his stinging bon mots sounding handcrafted rather than raspingly spontaneous) nor as inventive a director as Orson Welles. But this is still a rousing and endlessly amusing melodrama whose merciless demythologising of the tawdry trappings of fame remains acutely relevant in these days of transient celebrity.

Returning to the screen after two years away and injecting each epigram with real venom, Davis (who was only cast after Claudette Colbert damaged her back) gives a magisterial performance that seems founded upon the realisation that her own time in the spotlight was short. But she could never have anticipated that the film's future star was not to be Baxter, but a cameoing Marilyn Monroe, who reveals the gift for self-guying comedy that would become her forte as waspish critic George Sanders's bubble-headed companion.

Marilyn was very nervous about Gentlemen Prefer Blondes (1953), the follow-up to the star-making Niagara, as she wasn't sure she was up to the challenge of either the musical numbers or the deadpan comedy. However, just as he had done with Katharine Hepburn on Bringing Up Baby (1938), Howard Hawks guided Monroe towards her new screen persona and, in the process, subjected her to a total makeover to transform her from a pin-up into a star.

Despite its superficial complexities, the storyline is charmingly simple. Dorothy Shaw and Lorelei Lee are two little girls from Little Rock, whose trip to Europe is complicated by Lorelei's flirtation with Sir Francis Beekman (Charles Coburn) and Dorothy's discovery that Malone (Elliott Reed) is spying on her gold-digging pal for the father (Taylor Holmes) of her fiancé Gus Esmond (Tommy Noonan).

Inheriting a role for which Betty Grable was now deemed too old, Monroe departed from Anita Loos's stage characterisation of Lorelei to achieve a brand of innocent sensuality that was to become her trademark. But much of the credit goes to Hawks, who moulded her curves and charm to create a new kind of sex kitten, who was much less threatening than such blonde bombshells as Jean Harlow and Mae West. Indeed, he gave all the acerbic wisecracks to the sturdier Jane Russell as Dorothy, so that Monroe's humour seemed to be almost accidental (as it would do again in How to Marry a Millionaire). Yet, she worked hard to accomplish this spontaneity, with choreographer Jack Cole putting her through rigorous rehearsals.

However, the look of her most iconic number, `Diamonds Are a Girl's Best Friend', came about by chance, as Monroe had attracted such negative publicity after attending an awards ceremony in the gold lamé dress she wore in the movie that Twentieth Century-Fox insisted on ditching her original costume (a flesh-coloured leotard strategically studded with gems) for the pink gown that gave the routine its kitsch class (which was hijacked by Madonna for her `Material Girl' video).

The plot meanders once the principals reach Paris, with Russell's romance with Elliott Reed refusing to catch light. But she provides a selfless foil for Monroe's giddy scene-stealing and Charles Coburn turns in another polished display of harmless lechery as the splendidly nicknamed `Piggy'.

Finally, The Seven Year Itch is a key picture in the creation of the Monroe myth. Adapted by director Billy Wilder and George Axelrod from the latter's hit Broadway play, this was essentially an extension of the opening sequence in Wilder's 1942 farce, The Major and the Minor, in which Robert Benchley's home alone husband orders a scalp massage and fantasises about the pulchritude of his masseuse. There was also more than a hint of The Secret Life of Walter Mitty about the reveries that punctuated this dated, sniggeringly smutty, but occasionally amusing romp.

However, Wilder shifted the emphasis firmly on to the The Girl to exploit Marilyn Monroe's innocent sensuality and her gift for breathless comedy, which was just as well as her co-star, Tom Ewell, struggled throughout to convey a credible sense of guilty temptation, even though he had starred in the original stage production, opposite Vanessa Brown.

With wife Evelyn Keyes and son Butch Bernard away on vacation, middle-aged New Yorker Tom Ewell spends has spent a hot summer night with ditzy blonde neighbour Marilyn Monroe at an air-conditioned movie. As they leave the theatre, Monroe says she feels sorry for the monster in The Creature from the Black Lagoon, as he `just craved a little affection'. Further along the sidewalk, she stands astride an air vent over the subway and her plunging white dress billows up from the breeze of a passing train. She struggles to keep the skirt from revealing too much of her legs, but clearly revels in the sensation: `Sort of cools the ankles, doesn't it?' However, the censors forced Wilder to cut the line following the second train: `This one's even cooler! Must have been an express!' The scene reinforced Monroe's bombshell reputation, but ultimately wrecked her marriage to disapproving baseball legend, Joe DiMaggio.

Recognising Ewell's tendency towards theatricality, Wilder had attempted to cast Walter Matthau (whom he had tested with Gena Rowlands). But producer Charles K. Feldman nixed the idea and, as Wilder was on loan to Fox from Paramount, he had no bargaining power. He was similarly boxed into shooting in CinemaScope for the first time and didn't always make the most imaginative use of the additional space.

However, Wilder did coax a spirited performance out of Monroe, whose 23rd film proved to be her most successful to date. The triumph came at a cost, however, as husband Joe Di Maggio was so dismayed by the filming of the legendary subway vent sequence that he walked off the set, leaving Marilyn to complete the shoot before a vast watching crowd. Unsurprisingly, the footage was heavily censored, with only the billowing dress being shown on screen, consigning the iconic full-length view to the publicity campaign.

Wilder was equally frustrated by his inability to conclude the picture with a shot of the family maid finding a hair clip in Ewell's bed. But the Breen Office clearly felt it had been sufficiently lenient in permitting innumerable references to adultery, the risqué US Camera magazine and the permanent hotness of a girl who keeps her underwear in the ice box.