Hammer Horror, the long deceased master of gore is set to rise from the grave.

Hammer Horror films are celebrating the 40th anniversary of their first movie. And as a birthday present advertising mogul, Charles Saatchi, has signed a deal that will transform Hammer from a twitching cadaver into a global empire. Add to this the forthcoming bicentenary of the birth of Frankenstein's creator, Mary Shelley and the publishing centenary of Bram Stoker's Dracula - and we face one of the most horror-filled months of the century.

To celebrate, the first Hammer movies, The Curse of Frankenstein, Dracula and The Mummy are released on video for the first time this month. And hard-core obsessives can follow up with a season of Hammer movies on the Sci-Fi Channel. So what is the appeal of Hammer? Marcus Hearn, co-author of a new history of Hammer, puts its success down to three key elements : "First of all was horror: they were the first British company to produce an 'X' certificate film, The Quatermass Experiment in 1955. Then came colour with The Curse of Frankenstein in 1957, you could actually see blood for the first time, eyeballs dropped in jars and bodies dissolving in acid and finally sex. Dracula in 1958 was full of girls who enjoyed being bitten, giving orgasmic yelps, and leaving their windows open for him."

Housed in Pinewood and Bray Studios, a small team of producers and directors produced a steady and bloody stream of over 60 shuddering films boasting gore and cleavage. But it was the surprise success of one BBC serial adaptation, The Quatermass Experiment, which first revealed the potential of horror.

Looking for a follow-up, Michael Carreras, owner of Hammer, noticed that there had been no colour remake of Frankenstein or Dracula. They made The Curse of Frankenstein which broke box-office records. This vivid bloody colour-fest starred Peter Cushing as Baron Victor Frankenstein who brings his hideous monster (Christopher Lee) to life. The film, directed by Terence Fisher delighted in wallowing in its 'X' certificate. The critics hated it: "For sadists only" screamed The Telegraph. The public loved it. The follow-up, Dracula, featuring Christopher Lee as a sexually charged version of Bram Stoker's count, cost just pounds 80,000 to make but made profits of more than pounds 4m. Hammer became the world-market leader in horror movies, an achievement which was later acknowledged with a Queen's Award to Industry in 1968.

Production was stepped up and in the Sixties a decision was made to make the films back-to-back using the same cast, crew and locations. The release schedules were then carefully shuffled so that the audience didn't notice that Dracula lived in the same castle as Fu Manchu. The films became formulaic, leading even Christopher Lee to say in public that the series of Dracula movies had become repetitious and deadening. The series reaches its nadir with two Dracula films set in modern-day London: Dracula AD 72 and The Satanic Rites of Dracula left audiences giggling with delight rather than shivering with fear as high-budget American shockers like Rosemary's Baby and The Exorcist left Hammer looking, well, quaint.

Despite a few TV projects since, the last movie was made in 1979, but with Hollywood directors including Martin Scorsese and Wes Craven about to grasp the mantle, the beast looks set to rise again n