Centuries ago in France, the gypsy population would hold their own ceremonies such as the sacred marriage one where both bride and groom would mingle their own blood to prove their bond was true. However, in this area of Brittany there was a Count Sinistre (Hubert Noël) who imposed his own wants on the population, for he was a vampire who would rise from the grave to suck the blood from the living occasionally recruiting a victim to his cause. So it was one evening with the bride Tania (Carole Gray), who was doomed...
Although don't get comfortable with this time period, because while this starts out looking like a Hammer horror, soon after that introduction we are swept forward to the present, and a group of tourists visiting the sinister Count's stomping ground are set up as the next ones to be knocked down by his machinations. So whether the producers of this wanted to be different from that famed studio or whether they couldn't afford the historical trappings their rivals enjoyed, Devils of Darkness nonetheless had the distinction of being the first British vampire movie to be set in modern (for then) times.
Not that there was much else to distinguish it, for after a while you'll notice there may be quite a lot happening, but little of it was making an impression. The best you could hope for these days would be an appreciation of its kitsch, for mixed in with the vampirism was the then-fashionable chiller subject of the black arts, or Satanism as some termed it. The Count is a keen practitioner, which renders him more something out of Dennis Wheatley than Bram Stoker, but the results were some way short of The Devil Rides Out which would show up soon, not to mention Rosemary's Baby which was on the approach as well.
Our hero was in the middle-aged form of William Sylvester, dating this as in his advancing years it would be unlikely that he would be the protagonist of a horror flick with both eyes on the box office in later eras. He is best known now as Dr Floyd from 2001: A Space Odyssey, but he had a career as an ex-pat American for hire in British movies, and this wasn't his sole vampire film either as he starred in the willfully bloodless shocker The Hand of Night the same year he was in the Stanley Kubrick effort. This time, he was solid and dependable, but like the rest of it was not going to be anybody's preferred depiction of a fearless vampire hunter.
In fact, his Paul Baxter character spends a lot of time in the library back home in England as he tries to work out what power the talisman he liberated from the Count could possibly contain, which is bad news for the nation because Sinistre, posing as an artist, follows him and sets up his own coven among what could be best described as beatniks (set this a couple of years after and they would have been hippies judging by the joint we see passed around). Having lost two of his friends to the villain, Paul opts to rescue the potential human sacrifice Karen (Tracy Reed), the Count's model, but he does so without really engaging with the clique and remains steadfastly on the periphery for most of the story - those library books won't read themselves, after all. With some amusing special effects such as a rubber bat (shown up by a couple of real bats later on) and a hurricane from nowhere, there are intermittent points where the tone gets it right, but it was colourful yet flat otherwise. Music by Bernie Fenton.