It is impossible to overstate the importance of Bram Stoker's seminal novel Dracula when discussing the vampire genre. Its influence on the form and development of vampire movies was so great that we were into the 70s before English language films of the genre began to seriously shake off The Count and head in new directions.

When tracing this sub-genre of the horror film back to its origins, a key starting point is often Tod Browning's 1931 Dracula, which starred Bela Lugosi as the eponymous Count. There is a logic to this. Ask anyone to profile a typical vampire (and I've done this many times with media students and always get the same result) and they will give you Lugosi's Dracula every time – the dinner suit, the cape, the slicked-back hair, the East European accent, the old gothic castle, the bats, the coffin in the basement. Browning and Lugosi effectively shaped the movie vampire for decades to come, and even when films began to move in new directions, it was Lugosi's creation that remained the archetype and the basis for pretty much all genre parody to this day.

Dracula may have been the first vampire novel to be turned into a feature film, but if Browning's movie was the first officially sanctioned adaptation, then it was not the first film version per se. That honour, possibly, belongs to a 1920 Russian (or, some say, Hungarian) film that either never actually existed or has disappeared from the face of the earth, a fate that almost befell what many regard as the greatest vampire film of them all, F.W. Murnau's Nosferatu.

Nosferatu towers over the vampire genre but was so nearly lost to history. 'Freely adapted' from Stoker's novel, official permission was never obtained and Stoker's widow took the studio to court over copyright infringement and won. With the studio in bankruptcy, no monetary recompense could be secured, so the highly unusual (and for cinema itself, potentially catastrophic) decision was made to order all copies of the film destroyed. Fortunately for us all, a couple survived (exact details are hazy here and no two stories appear to agree completely), one of which eventually made its way to America and to Universal studios, where it was to influence key aspects of Browning's film.

For the first fifty years, the development of the vampire genre was gradual, following rules that were defined by its earliest works but modifying them on a film-by-film basis. Writing in Narrative and Genre, Nick Lacey neatly summed up the concept of genre development with the simple phrase "the same but different" – when an audience watches a movie they arrive with certain expectations, an understanding of the rules of the genre in which it sits but coupled with the hope that it will nonetheless deliver something new. Genre evolves through an unspoken collaboration between the audience and the film-makers, and those producing films certainly understand this, knowing they have to give the audience what they want, but not always what they expect.

In retrospect, Nosferatu cannot really be regarded as being part of this process and stands as a one-off – a single vampire movie does not a genre make, and when it really kicked off with Browning's Dracula, Nosferatu was effectively a lost film. But Nosferatu was also a European film, and although many of Hollywood's early directors either hailed from Europe or were influenced by its cinema, the films themselves did not reach a fraction of the world audience of their Hollywood bretheren, a situation that has changed little in the subsequent decades. It is only through the distancing effect of time that Nosferatu's essential role in genre development can be properly assessed, as well as its influence on key later works. In standing alone, uninfluenced by preceding genre films (simply because there were none), it remains the most singular work in the first fifty years of the genre's history, in its style, its visual inventiveness and its subtextual complexity. And in the bold nature of its adaptation of the classic text, it now seems years ahead of its time.

Nosferatu's free adaptation of Stoker's novel changed not only the names of all of the key protagonists but also many of their roles in the narrative. In the novel, young solicitor Jonathan Harker travels to Transylvania to close a deal with Count Dracula on a property located close to his own in Whitby. This element remains in Murnau's film, but here Whitby becomes Wisborg and Harker is Thomas Hutter, the almost child-like husband of mournful Ellen, sent off to secure the deal with Dracula substitute Count Orlock by his greedy, almost possessed boss, Broker Knock. Knock is secretly in league with Orlock, and his increasing madness eventually places him in an asylum, where he fulfils the role of Dracula's insect-eating servant Renfield from Stoker's original.

Hutter's journey to Castle Orlock, via an inn at a nearby village populated by frightened and superstitious locals, is very much how things would play from this point on. He is effectively blinded by cheerful optimism at the personal advancement this deal might bring him, prompting him to brush off the warnings of these simple peasant folk and mockingly hurl to the floor a book he finds in his room that warns of vampires and other creatures of the night. The next day, he is delivered to an arranged meeting place by an agitated coachman, who is keen to flee before the sun goes down, and is met by a second coach and a sinister-looking driver, who conducts him at impossible speed to Orlock's remote castle.

This is our first encounter with the film's greatest and most memorable creation: Orlock himself. As played by Max Schreck, the inspiration for Orlock can certainly be found in the novel, but as a screen creation he bears little resemblance to the suave ladykiller of Lugosi et al. With his bald head, pointed ears, extended fingernails and long, centrally located fangs, Orlock is like a rat in human form, a truly supernatural creature whose very image is enough to disturb anyone with an ounce of sense, something Hutter seems to have left back in Wisborg. As they discuss the deal over dinner, Hutter accidentally cuts his finger and Orlock's reaction is instantaneous and disturbing – he grabs Hutter's finger and sucks the blood from it, causing Hutter to retreat in alarm. Orlock slowly advances on him and the screen fades to black, and we are left to speculate on the nature of the assault that follows. Was this a vampiric attack or a monstrous seduction? The next morning Hutter is left with no memory of the incident and dismisses the two holes in his neck as insect bites.

This is a key scene altered from the novel that was to be recreated in Browning's 1931 version. In the novel Harker cuts himself shaving, but Browning also chose to stage the scene during contractual discussions over dinner, clear evidence that at least some of those involved in the production had seen Murnau's original. But then Browning was to play his own specific games with Dracula's characters and structure, as was Terence Fisher in Hammer's spitited 1958 reworking.

It is with Orlock's second attack on Hutter that the film really comes into its own and when Murnau starts to show just how ahead of the game he was, in horror imagery, generic subtext, and in his striking use of film as a storytelling medium. Hutter, unable to sleep, opens his bedroom door to reveal the distant figure of Orlock, standing bolt upright, eyes staring straight ahead, like a creature that has been shocked to death. As Orlock slowly advances, Hutter reacts by cowering in his bed, pulling the bedclothes up like a frightened child, until swathed by Orlock's demonic shadow. At the same time, back in Hutter's home town of Wisborg, Ellen wakes with a start and begins sleepwalking. Restrained by her friends, she suddenly calls out to her husband, and Murnau cross-cuts between the two locations, establishing a very real connection between the attack on Thomas and Ellen's anguish. In a genuinely astonishing edit, Ellen, in her bedroom, reaches out to frame left for Thomas and we cut to Orlock, having just finished with Thomas, turning to look frame right, and he seems to be looking directly at Ellen, despite the hundreds of miles between them. This almost telepathic connection is echoed later when Ellen says "He is near" – it is never certain whether she is referring to the returning Thomas or the approaching Orlock.

Most adaptations of the Dracula story have split themselves evenly between the Harker's encounter with the Count in Transylvania and the cat-and-mouse games fought on English soil between Dracula and his enemies, who are led by knowledgeable Professor Van Helsing. Nosferatu is probably unique in that it devotes so little screen time to this second half of the story, and we are 69 minutes into a 90 minute film before Orlock even sets foot in Wisborg. When he does so he brings more than the threat of vampirism – he brings disease in the form of the plague, a real world contangion that was spread by the very creature that he most resembles. Orlock comes to Wisborg solely to possess Ellen (quite why he becomes so obsessed with her on seeing her picture is not clear), but he is more than a vampire looking for fresh victims – he arrives as an angel of death, his very presence laying waste to everything he encounters. In generic terms, Murnau was once again ahead of his time. 55 years before Kathryn Bigelow presented vampirism as an AIDS-like infection that could be passed on through body fluids in Near Dark, Murnau had painted a most vivid and convincing picture of the vampire as a spreader of lethal disease.

Orlock remains the most extraordinary film incarnation of Dracula and in some ways its most iconic, despite Lugosi's genre-shaping performance. With dialogue sparsely represented by title cards, the emotions, fears and intentions of the characters are all externalised through Albin Grau's costumes and sets, Güther Krampf and Fritz Arno Wagner's cinematography, Murnau's direction, and Schreck's central performance, resulting in an expressionistic masterpiece whose imagery has become a part of film lore: Orlock walking the deck of the death ship, rising bolt upright from his coffin, or emerging slowly from the hold on its arrival in Wisborg; his hunched shadow as he climbs the stairs towards Ellen's bedroom; the still startling symbolic shadow that reaches out and grasps Ellen's heart; Orlock ghoulishly feeding off Ellen as dawn approaches. All are all moments that once seen are never forgotten, their impact as imagery given extra meat by their potent thematic and symbolic subtext.

As something of an outsider in generic terms, Nosferatu nonetheless contains some of the genre's most recognisable iconography: Orlock sucks the blood of his victims by biting their necks; it is suggested that he can shape-shift into a wolf (though this is never seen); he lives in an old castle and sleeps in a coffin; he has supernatural powers and can open doors telekenetically and even pass through closed ones; terrified locals try to warn unwary travelers, who fail to take heed. The notion that vampires can be destroyed by sunlight also originated here (in the novel, a less powerful Count Dracula walked freely around the streets of London in the daytime), which has since become one of the genre's few unbreakable rules. Another key genre element, however, is completely ignored, with religion offering no comfort or protection – indeed, it is barely mentioned here, the cross that was to protect vampire hunters and potential victims from Browning's film onwards appearing here merely as a headstone (in one of the film's most striking images, as Ellen waits in a seaside graveyard for Thomas's return), or almost coincidentally as a chalk mark on the door of a plague house.

Key characters from the novel and later films play different roles in Marnau's story. Van Helsing stand-in Professor Bulwer is, in narrative terms, completely ineffectual, his function here being purely to ground the vampire in some sort of reality by comparing him to stranger scientific curiosities like the Venus Fly Trap – at no point is he even proposed as a potential adversary for the Count. Ellen, on the other hand, is a far stronger character than most of her successors, with the generic tradition of women as victims who scream, faint, become possessed and ultimately collaborate with their attacker having no place here. Though clearly affected by Orlock's controlling power, Ellen fights it with every ounce of her strength, and invites the Count to her bedroom not as a manipulated victim or a bride with an unfulfilled longing, but with the intention of keeping him at her bedside until the break of dawn in order to destroy him. She does so, as suggested by the narrative, as a 'pure' maiden, suggesting an unconsummated marriage, a proposal reflected in her sad demeanour and her otherwise inexplicable reaction to the cut flowers presented to her early in the film by her husband – in a childless, barren marriage, the sight of life being cut down, whatever the form, is painful for her. Orlock is the opposite of Thomas in this respect, a potent, aggressive force who can deliver what Thomas cannot, but at a terrible price.

Time has moved on and the nature of the cinematic form has drastically changed in the century since it's birth. It is unlikely that modern viewers would be as frightened by Nosferatu in the way its original audience must have been. But much of it does remain genuinely chilling – Murnau and Schreck have created a film in which nightmare imagery replaces the everyday, pictures raided from our dreams and presented on screen for all to see.

If it remained widely unseen for decades, Nosferatu was eventually to make its mark on modern cinema and television. In 1979, it was remade by maverick German director Werner Herzog with Klaus Kinski in the lead, a very different film to Murnau's original that has always divided opinion but is fascinating in its own right. Schreck's Orlock became the basis for the vampire Kurt Barlow in Tobe Hooper's mini-series adaptation of Stephen King's Salem's Lot (in the novel, Barlow is a more classical vampire), and in the first episode of Buffy the Vampire Slayer, the demon known as The Master is clearly modeled on Orlock. In Batman Returns, Christopher Walken's character is named Max Schreck in tribute to this film's lead actor, and the recent Shadow of a Vampire fashioned its narrative around the making of Nosferatu, suggesting that Schreck was not an actor but a genuine creature of the night. Not so long ago the BBC screened a commercial for one of its own services that was fashioned around a key sequence from the film, and Orlock has even turned up intermittently in the sketch series The Fast Show to threaten a maiden in her bed and then deliver a comic line that ends with the word "Monster!"

Nosferatu was the first major vampire movie and remains in many ways the genre's most extraordinary achievement. In its visuals, its expressionist sets and acting, its narrative and thematic depth, its sometimes groundbreaking editing, it was years ahead of its time, and its importance in genre history has only in recent years been fully appreciated. Remember too that every film that followed had previous genre works to draw on or react to – Nosferatu was a true original, and every frame in the film is the result of the startling vision of Murnau and his collaborators. For my money, despite some stiff competition, Nosferatu is quite simply the vampire movie.

Let's get one thing straight. If you're expecting a restoration of the quality of Eureka's recent two-disc version of Fritz Lang's M then forget it.* Almost every copy of Nosferatu was destroyed and every subsequent print has been struck from one of the very few that survived, and they were in far from perfect shape. Scratches are plentiful, as are dust spots and frame damage. On top of that, there are quite a few frame jumps and the exposure can wander dramatically in places from one second to the next. But considering the film's age and history, this is par for the course and shouldn't harm your appreciation of the work itself.

We have two versions to evaluate here, though it could be argued that there are three, as the Eureka release includes two discs, one presenting the film in monochrome, the other with a sepia tint. I'm really not sure of the thinking behind this, unless it's the tinting equivalent of having a full screen and a widescreen print in the same box, so you get whichever one you prefer. Of course what we'd actually prefer is to see the print as it was projected in cinemas when first shown, and this is what the transfer on the BFI disc claims to be.

Nosferatu was shot in the days when film stock was just too slow for film-makers to shoot by artificial light, and filming was generally carried on roofless exterior sets. Shadow of the Vampire, in order to accommodate the idea that Schreck himself was a vampire and unable to walk freely in the daytime, suggested that the film was shot by artificial light, but this was not the case. This need to film by daylight should prove restrictive in scenes supposedly set at night, as common sense would suggest that the sky should never be in shot at any time, as this would instantly give the game away. Murnau, however, refused to be restricted by this, and one of the film's most iconic shots has Orlock walking the deck of the death ship, viewed from low down in the hold. The sky dominates this shot and it is clearly daylight, so how on earth is sunlight used to destroy Orlock at the end of the film? If the ship scene had to be shot in the day, how did an audience new to the whole concept of vampire movies know that this daytime shot was actually meant to be night? According to film historians the answer lay in tinting – scenes set at night would have a blue tint, whereas daytime scenes would have a warmer hue. These were indicators that a 1920s audience would have understood, but which have been lacking from every print of Nosferatu shown since those early screenings, and it is this that the BFI disc attempts to rectify. Whether those indicators work as well for a modern audience is debatable, but it's good to have the chance to view the film is it was meant to be shown.

As to which version is the best, well that's a different story. The BFI disc has to come recommended as the most authentic, but in terms of clarity, detail and contrast, the black-and-white print on the Eureka 2-disc set definitely wins out. The tinting inevitably takes something away from the picture in terms of fine detail – the same is true of the tinted print in the Eureka package. So it comes down to personal preference: if you want to see the film as it was originally screened, then go for the BFI disc, but if you want clarity and detail, then Eureka disc is the one for you.

The BFI disc (above) and the Eureka disc (below)

But there's another issue here. The picture on the BFI disc is windowboxed within a black border, which helps with TV overscan but sometimes crops information on two or more sides, though this varies wildly and accosionally actually appears to have more picture information than the Eureka transfer. The above screen grabs illustrate both this and the differences in sharpness and detail clarity.

This seems an odd section to have for a silent film, but both discs have music scores, and they are different enough in style to possibly be the deciding factor in which disc is for you.

The Eureka disc features an electronic music track that is available in Dolby stereo 2.0 (this option is only available on the untinted print on disc 2) or 5.1 surround. Whether this is appropriate for the film is debatable, as it is music that couldn't possibly have been heard on its release, and unlike Giorgio Moroder's electronic score for his recut of Lang's Metropolis, which as a futuristic story could logically embrace electronic musical accompaniment, Murnau's gothic vision is rooted in its time and would seem to demand a more traditional approach. Having said that, I found much of Gérard Hourbette and Thierry Zaboitzeff's score here very effective. If the purpose of a music track is to emphasise and direct the emotions of the audience then the one here frequently succeeds, the deep, sinister electronic notes really adding to the sense of menace in the early stages. As the film progressed I became less enthralled, as the score veers towards the avant-garde, losing me completely with the use of what sounded like typewriter keys being randomly tapped. I have no problem with the concept of avant-garde music – as a lifelong fan of Giorgi Ligerti I have watched a music performance that included screaming and the smashing of crockery and enjoyed it immensely – but with film scores it has to be appropriate, and here I have to question whether that is the case.

The BFI disc sports an orchestral score by James Bernard, whose work for Hammer studios was so much part of their corporate identity. This is certainly a more traditional musical accompaniment and on the whole is more effective and more subtle than the electronic work on on Eureka's disc, but for vampire movie aficionados there is a down side, and that's one of familiarity. It's a fine score, no question, but its similarity to Bernard's score for Hammer's Dracula is impossible to ignore, and as a huge fan of Hammer's version and Hammer films in general, it at times felt almost as if the music from the later film had been simply adapted for this earlier work. Again, it all comes down to personal preferences, and this is still a very evocative and appropriate score, though it's a tad disappointing to find it presented in Dolby 2.0 rather than the room-filling 5.1 it deserves.

Here again, the two discs differ a great deal. I'll look at the discs in the order of their release, which puts the Eureka DVD up front. All of the extras are on disc 1, which contains the sepia print, a colouration that has also been applied to almost every extra here.

First up is an audio commentary on the film and its background, but by whom is never stated. It plays in some ways like a lecture on the film and presents a great deal of information about the narrative, the making of the film and the various subtextual readings. Much of this is really interesting, but is delivered not by an academic, as on the Universal classic horror releases, but what sounds like an actor attempting to impersonate Valantine Dyall. This gives the whole thing a slightly artificial feel, but it is interesting.

There are two trailers, one for Nosferatu, featuring extracts from the film and a voice-over from the Valentine Dyall wannabe and was created to promote this very disc. It is framed 1.33:1 and runs for 2 minutes 47 seconds. Inspiring it is not. The other is for E. Elias Merhidge's Shadow of the Vampire, whose release coincided with that of this disc and is a logical inclusion considering its plot was based around the shooting of Murnau's film. This is also famed 1.33:1, is 1 minute 30 seconds long, and the only extra on the disc not awash with sepia tinting. It sells the film rather well.

Nosferatu Recaptured has two subsections. The cheesily titled NosferaTour runs for just over 13 minutes and briefly puts a face to Valentine Dyall Jnr. before settling down into an interesting trip around the locations at which Nosferatu was shot. Freeze frames of the film are compared with historical and modern photographs of the actual locations, while Mr. Dyall tells us about what we are watching, giving some historical background and information on the present condition or fate of the buildings, including one location's link to Hammer's first Dracula film. It's an enjoyable extra, and made me think about taking a holiday to hunt out the locations for myself (I did this several years ago for the superb British war film Went the Day Well?), but you can't help wishing they'd gone there with a video camera and made a full-blooded featurette.

A Visual Legacy runs for just over 4 minutes and looks at the poster art and the original sketches by art director Albin Grau and how close they were to Murnau's final film images, giving a clear indication of Grau's contribution to the look of the film. Again, this is narrated by Dyall Jnr.

Origins of Vampires gives a fairly detailed though far from exhaustive textual history of vampire lore, using the rise of Vlad Dracul as its kicking off point, though no mention is made of the legend's origins in various cultures before 1431. It's still an interesting read, and even though written in gothic script as if part of an old parchment, is still very legible.

Nosferatu's Controversy is a textual extra very much in the style of the Origins of Vampires one, giving a brief summary of the legal action taken to destroy all prints of the film and one version of how it survived. Nosferatu's Controversy and Origins of Vampires also appear on disc 2, but without the sepia tint.

And so on to the BFI disc...

Christopher Frayling on Nosferatu has writer Sir Christopher Frayling, a Nosferatu enthusiast and author of the preface in the Penguin Classics edition of Stoker's Dracula, waxing lyrical about what is clearly one of his favourite films. Frayling is a fine communicator and his enthusiasm is infectious – he covers a lot of ground well, including the various subtextual readings of the film, not all of which he agrees with. Divided into subject areas by title cards and nicely illustrated with clips from the film and influential artwork, this is a very good extra and a very detailed look at the key influences on the film's look and structure, as well as some of the possible readings. The featurette is presented 1.33:1 and runs for just over 24 minutes.

F W Murnau is a reasonably thorough text-based biography of the great German director, written by critic and writer Philip Kemp. A full filmography is included at the end.

James Bernard and the Music is also text-based and is a three-page contribution by the composer of the score for the BFI disc on his approach to the project, plus a brief biography and full filmography of Bernard himself.

Enno Patalas on restoring Nosferatu is a detailed essay on the restoration of the film, which is stored on the DVD in PDF format and needs a computer with a DVD-ROM drive to access. You will need Adobe Acrobat Reader to access it, unless you have a Mac with OSX, which opens PDF files without extra software. It's worth getting access to this extra if you are interested in the restoration process, as it does make for very interesting reading.

The Web Link is a bit of a cheat, as clicking on it, even if you are running the disc on a DVD-ROM drive, just supplies you with a message telling you to place the disc in your computer and locate and open the file Nosferatu.html. Do this, though, and you will be supplied with a link that takes you to the BFI's web site, and this approach does at least make the link accessible to all computers and operating systems, not just PCs.

For a young audience raised on Buffy and Blade and with little knowledge of genre history, German Expressionism, or even silent cinema, Nosferatu might to prove initially inaccessible. But trust me, if you really care about the vampire genre as a whole, this will pass. For genre fans who know their film history and their vampire lore, this is the godfather of vampire movies, a gorgeous gothic creation and one of film history's most darkly beautiful works. It remains so in part through a bizarre twist of fate, for had Stoker's widow not tried to have all copies destroyed, and had it been the worldwide success that Browning's Dracula became, then who knows, maybe Max Schreck rather than Bela Lugosi would have defined the movie vampire for decades to come, until that figure also became a cliché and fit only for parody. As result, while Lugosi's Dracula is now a figure of fun, Schreck's remains a genuinely creepy and even disturbing creation, a supernatural embodiment of vampirism as a potent and deadly force, and a creature to be genuinely afraid of.

As for which disc to go for, well it's all a matter of personal preference, but recently most I have leaned towards the BFI disc for its more classical score and the restoration of the original tinting, as well as Christopher Frayling's informative featurette. But the Eureka disc sometimes has more picture information, a clearer black-and-white print and a very interesting if somewhat overly 'performed' commentary. Which of course means only one thing if you are a real fan – buy them both.

* Some years after I wriote this review, German film restoration house Friedrich-Wilhelm-Murnau-Stiftung went to work on the film and delivered the very reconstruction I I here believed we would never see, which was released on DVD by Eureka! under their Masters of Cinema banner. personally I was overjoyed to eat my words.